Hi!

Last week wlroots 0.19.0-rc1 has been released! It includes the new color management protocol, however it doesn't include HDR10 support because the renderer and backend bits haven't yet been merged. Also worth noting is full explicit synchronization support as well as the new screen capture protocols. I plan to release new release candidates weekly until we're happy with the stability. Please test!

Sway is also getting close to its first release candidate. I plan to publish version 1.11.0-rc1 this week-end. Thanks to Ferdinand Bachmann, Sway no longer aborts on shutdown due to dangling signal listeners. I've also updated my HDR10 patch to add an output hdr command (but it's Sway 1.12 material).

I've spent a bit of time on libicc, my C library to manipulate ICC profiles. I've introduced an encoder to make it easy to write new ICC profiles, and used that to write a small program to create an ICC profile which inverts colors. The encoder doesn't support as many ICC elements as the decoder yet (patches welcome!), but does support many interesting bits for display profiles: basic matrices and curves, lut16Type elements and more advanced lutAToBType elements. New APIs have been introduced to apply ICC profile transforms to a color value. I've also added tests which compare the results given by libicc and by LittleCMS. For some reason lut16Type and lutAToBType results are multiplied by 2 by LittleCMS, I haven't yet understood why that is, even after reading the spec in depth and staring at LittleCMS source code for a few hours (if you have a guess please ping me). In the future I'd like to add a small tool to convert ICC profiles to and from JSON files to make it easy to create new files or adjust exist ones.

Version 0.9.0 of the soju IRC bouncer has been released. Among the most notable changes, the database is used by default to store messages, pinned/muted channels and buffers can be synchronized across devices, and database queries have been optimized. I've continued working on the Goguma mobile IRC client, fixing a few bugs such as dangling Firebase push subscriptions and message notifications being dismissed too eagerly.

Max Ehrlich has contributed a mako patch to introduce a Notifications property to the mako-specific D-Bus API, so that external programs can monitor active notifications (e.g. display a count in a status bar, or display a list on a lockscreen).

That's all I have in store, see you next month!

16 Apr 2025 10:00pm GMT

It's CLover.

16 Apr 2025 12:00am GMT

We are excited about the Fedora Workstation 42 released today. Having worked on some great features for it.

Fedora Workstation 42 HDR edition
I would say that the main feature that landed was HDR or High Dynamic Range. It is a feature we spent years on with many team members involved and a lot of collaboration with various members of the wider community.

GNOME Settings menu showing HDR settings

The fact that we got this over the finish line was especially due to all the work Sebastian Wick put into it in collaboration with Pekka Paalanen around HDR Wayland specification and implementations.
Another important aspect was tools like libdisplay which was co-created with Simon Ser, with others providing more feedback and assistance in the final stretch of the effort.

HDR setup in Ori and Will of the Wisps

That said a lot of other people at Red Hat and in the community deserve shout outs for this too. Like Xaver Hugl whose work on HDR in Kwin was a very valuable effort that helped us move the GNOME support forward too. Matthias Clasen and Benjamin Otte for their work on HDR support in GTK+, Martin Stransky for his work on HDR support in Firefox, Jonas Aadahl and Olivier Fourdan for their protocol and patch reviews. Jose Exposito for packaging up the Mesa Vulkan support for Fedora 42.

One area that should benefit from HDR support are games. In the screenshot about you see the game Ori and the Will of the Wisps which is known for great HDR support. Valve will need to update to a Wine version for Proton that supports Wayland natively though before this just works, at the moment you can get it working using gamescope, but hopefully soon it will just work under both Mutter and Kwin.

Also a special shoutout to the MPV community for quickly jumping on this and releasing a HDR capable video player recently.

MPV video player playing HDR content

Of course getting Fedora Workstation 42 to out with these features is just the beginning, with the baseline support it now is really the time when application maintainers have a real chance of starting to make use of these features, so I would expect various content creative applications for instance to start having support over the next year.

For the desktop itself there are also open questions we need to decide on like:

• Format to use for HDR screenshots
• Better backlight and brightness handling
• Better offloading
• HDR screen recording video format
• How to handle HDR webcams (seems a lot of them are not really capable of producing HDR output).
• Version of the binary NVIDIA driver released supporting the VK_EXT_hdr_metadata and VK_COLOR_SPACE_HDR10_ST2084_EXT Vulkan extension on Linux
• A million smaller issues we will need to iron out

Accessibility
Our accessibility team has been hard at work trying to ensure we have a great accessibility story in Fedora Workstation 42. Our accessibility team with Lukas Tyrychtr and Bohdan Milar has been working hard together with others to ensure that Fedora Workstation 42 has the best accessibility support you can get on Linux. One major effort that landed was the new keyboard monitoring interface which is critical for making Orca work well under Wayland. This was a collaboration of between Lukas Tyrychtr, Matthias Clasen and Carlos Garnacho on our team. If you are interested in Accessibility, as a user or a developer or both then make sure to join in by reaching out to the Accessibility Working group

PipeWire
PipeWire also keeps going strong with continuous improvements and bugfixes. Thanks to the great work by Jan Grulich the support for PipeWire in Firefox and Chrome is now working great, including for camera handling. It is an area where we want to do an even better job though, so Wim Taymans is currently looking at improving video handling to ensure we are using the best possible video stream the camera can provide and handle conversion between formats transparently. He is currently testing it out using a ffmpeg software backend, but the end goal is to have it all hardware accelerated through directly using Vulkan.

Another feature Wim Taymans added recently is MIDI2 support. This is the next generation of MIDI with only a limited set of hardware currently supporting it, but on the other hand it feels good that we are now able to be ahead of the curve instead of years behind thanks to the solid foundation we built with Pipewire.

Wayland
For a long time the team has been focused on making sure Wayland has all the critical pieces and was functionality wise on the same level as X11. For instance we spent a lot of time and effort on ensuring proper remote desktop support. That work all landed in the previous Fedora release which means that over the last 6 Months the team has had more time to look at things like various proposed Wayland protocols and get them supported in GNOME. Thanks to that we helped ensure the Cursor Shape Protocol and Toplevel Drag protocols got landed in time for this release. We are already looking and what to help land for the next release, so expect a continued acceleration in Wayland protocol adoption going forward.

First steps into AI
So an effort we been plugging away at recently is starting to bring AI tooling to Open Source desktop applications. Our first effort in this regard is Granite.code. Granite.code is a extension for Visual Studio Code that sets up a local AI engine on your system to help with various tasks including code generation and chat inside Visual Studio Code. So what is special about this effort is that it relies on downloading and running a copy of the open source AI Granite LLM model to your system instead on relying on it being run in a cloud instance somewhere. That means you can use Granite.code without having to share your data and work with someone else. Granite.code is still very early stage and it requires a NVIDIA or AMD GPU with over 8GB of video ram to use under Linux. (It also runs under Windows and MacOS X). It is still in a pre-release stage, we are waiting for the Granite 3.3 model update to enable some major features for us before we make the first formal release, but for those willing to help us test you can search for Granite in the Visual Studio Code extension marketplace and install it.
We are hoping though that this will just the starting point where our work can get picked up and used by other IDEs out there too and also we are thinking about how we can offer AI features in other parts of the desktop too.

Granite.code running on Linux

15 Apr 2025 2:38pm GMT

Linux 6.14 is the second release of 2025, and as usual Igalia took part on it. It's a very normal release, except that it was release on Monday, instead of the usual Sunday release that has been going on for years now. The reason behind this? Well, quoting Linus himself:

I'd like to say that some important last-minute thing came up and delayed things.

But no. It's just pure incompetence.

But we did not forget about it, so here's our Linux 6.14 blog post!

A part of the development cycle for this release happened during late December, when a lot of maintainers and developers were taking their deserved breaks. As a result of this, this release contains less changes than usual as stated by LWN as the "lowest level of merge-window activity seen in years". Nevertheless, some cool features made through this release:

• NT synchronization primitives: Elizabeth Figura, from Codeweavers, is know from her work around improving Wine sync functions, like mutexes and semaphores. She was one the main collaborators behind the futex_waitv() work and now developed a virtual driver that is more compliant with the precise semantics that the NT kernel exposes. This allows Wine to behave closer to Windows without the need to create new syscalls, since this driver uses ioctl() as the front-end uAPI.
• RWF_UNCACHED: Linux has two ways of dealing with storage I/O: buffered I/O (usually the preferred one) that stores data in a temporary buffer and regularly syncs the cache data with the device; and direct I/O that doesn't use cache and always writes/reads synchronously with the storage device. Now a new mixed approach is available: uncached buffered I/O. This method is aimed to have a fast way to write or read data that will not be needed again in the short term. For reading, the device writes data in the buffer and as soon as the user finished reading the buffer, it's cleared from the cache. For writing, as soon as userspace fills the cache, the device reads it and removes it from the cache. In this way we still have the advantage of using a fast cache but reducing the cache pressure.
• amdgpu panic support: AMD developers added kernel panic support for amdgpu driver, "which displays a pretty user friendly message on the screen when a Linux kernel panic occurs" instead of just a black screen or a partial dmesg log.

As usual Kernel Newbies provides a very good summary, you should check it for more details: Linux 6.14 changelog. Now let's jump to see what were the merged contributions by Igalia for this release!

DRM

For the DRM common infrastructure, we helped to land a standardization for DRM client memory usage reporting. Additionally, we contributed to improve and fix bugs found in drivers of AMD, Intel, Broadcom, and Vivante.

AMDGPU

For the AMD driver, we fixed bugs experienced by users of Cosmic Desktop Environment on several AMD hardware versions. One was uncovered with the introduction of overlay cursor mode, and a definition mismatch across the display driver caused a page-fault in the usage of multiple overlay planes. Another bug was related to division by zero on plane scaling. Also, we fixed regressions on VRR and MST generated by the series of changes to migrate AMD display driver from open-coded EDID handling to drm_edid struct.

Intel

For the Intel drivers, we fixed a bug in the xe GPU driver which prevented certain type of workarounds from being applied, helped with the maintainership of the i915 driver, handled external code contributions, maintained the development branch and sent several pull requests.

Raspberry Pi (V3D)

We fixed the GPU resets for the Raspberry Pi 4 as we found out to be broken as per a user bug report.

Also in the V3D driver, the active performance monitor is now properly stopped before being destroyed, addressing a potential use-after-free issue. Additionally, support for a global performance monitor has been added via a new DRM_IOCTL_V3D_PERFMON_SET_GLOBAL ioctl. This allows all jobs to share a single, globally configured perfmon, enabling more consistent performance tracking and paving the way for integration with user-space tools such as perfetto.

A small video demo of perfetto integration with V3D

etnaviv

On the etnaviv side, fdinfo support has been implemented to expose memory usage statistics per file descriptor, enhancing observability and debugging capabilities for memory-related behavior.

sched_ext

Many BPF schedulers (e.g., scx_lavd) frequently call bpf_ktime_get_ns() for tracking tasks' runtime properties. bpf_ktime_get_ns() eventually reads a hardware timestamp counter (TSC). However, reading a hardware TSC is not performant in some hardware platforms, degrading instructions per cycyle (IPC).

We addressed the performance problem of reading hardware TSC by leveraging the rq clock in the scheduler core, introducing a scx_bpf_now() function for BPF schedulers. Whenever the rq clock is fresh and valid, scx_bpf_now() provides the rq clock, which is already updated by the scheduler core, so it can reduce reading the hardware TSC. Using scx_bpf_now() reduces the number of reading hardware TSC by 50-80% (e.g., 76% for scx_lavd).

Assorted kernel fixes

Continuing our efforts on cleaning up kernel bugs, we provided a few fixes that address issues reported by syzbot with the goal of increasing stability and security, leveraging the fuzzing capabilities of syzkaller to bring to the surface certain bugs that are hard to notice otherwise. We're addressing bug reports from different kernel areas, including drivers and core subsystems such as the memory manager. As part of this effort, several fixes were done for the probe path of the rtlwifi driver.

Check the complete list of Igalia's contributions for the 6.14 release

Authored (38)

Changwoo Min

• sched_ext: Relocate scx_enabled() related code
• sched_ext: Implement scx_bpf_now()
• sched_ext: Add scx_bpf_now() for BPF scheduler
• sched_ext: Add time helpers for BPF schedulers
• sched_ext: Replace bpf_ktime_get_ns() to scx_bpf_now()
• sched_ext: Use time helpers in BPF schedulers
• sched_ext: Fix incorrect time delta calculation in time_delta()

Christian Gmeiner

• drm/v3d: Stop active perfmon if it is being destroyed
• drm/etnaviv: Add fdinfo support for memory stats
• drm/v3d: Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL

Luis Henriques

• fuse: fix possible deadlock if rings are never initialized

Maíra Canal

• drm/v3d: Fix performance counter source settings on V3D 7.x
• drm/v3d: Fix miscellaneous documentation errors
• drm/v3d: Assign job pointer to NULL before signaling the fence
• drm/v3d: Don't run jobs that have errors flagged in its fence
• drm/v3d: Set job pointer to NULL when the job's fence has an error

Melissa Wen

• drm/amd/display: fix page fault due to max surface definition mismatch
• drm/amd/display: increase MAX_SURFACES to the value supported by hw
• drm/amd/display: fix divide error in DM plane scale calcs
• drm/amd/display: restore invalid MSA timing check for freesync
• drm/amd/display: restore edid reading from a given i2c adapter

Ricardo Cañuelo Navarro

• mm,madvise,hugetlb: check for 0-length range after end address adjustment
• mm: shmem: remove unnecessary warning in shmem_writepage()

Rodrigo Siqueira

• MAINTAINERS: Change my role from Maintainer to Reviewer
• mailmap: Add entry for Rodrigo Siqueira

Thadeu Lima de Souza Cascardo

• wifi: rtlwifi: do not complete firmware loading needlessly
• wifi: rtlwifi: rtl8192se: rise completion of firmware loading as last step
• wifi: rtlwifi: wait for firmware loading before releasing memory
• wifi: rtlwifi: fix init_sw_vars leak when probe fails
• wifi: rtlwifi: usb: fix workqueue leak when probe fails
• wifi: rtlwifi: remove unused check_buddy_priv
• wifi: rtlwifi: destroy workqueue at rtl_deinit_core
• wifi: rtlwifi: fix memory leaks and invalid access at probe error path
• wifi: rtlwifi: pci: wait for firmware loading before releasing memory
• Revert "media: uvcvideo: Require entities to have a non-zero unique ID"
• char: misc: deallocate static minor in error path

Tvrtko Ursulin

• drm/amdgpu: Use DRM scheduler API in amdgpu_xcp_release_sched
• drm/xe: Fix GT "for each engine" workarounds

Reviewed (36)

André Almeida

• ASoC: cs35l41: Fallback to using HID for system_name if no SUB is available
• ASoC: cs35l41: Fix acpi_device_hid() not found

Christian Gmeiner

• drm/v3d: Fix performance counter source settings on V3D 7.x
• drm/etnaviv: Convert timeouts to secs_to_jiffies()

Iago Toral Quiroga

• drm/v3d: Fix performance counter source settings on V3D 7.x
• drm/v3d: Assign job pointer to NULL before signaling the fence
• drm/v3d: Don't run jobs that have errors flagged in its fence
• drm/v3d: Set job pointer to NULL when the job's fence has an error

Jose Maria Casanova Crespo

• drm/v3d: Assign job pointer to NULL before signaling the fence

Luis Henriques

• fuse: rename to fuse_dev_end_requests and make non-static
• fuse: Move fuse_get_dev to header file
• fuse: Move request bits
• fuse: Add fuse-io-uring design documentation
• fuse: make args->in_args[0] to be always the header
• fuse: {io-uring} Handle SQEs - register commands
• fuse: Make fuse_copy non static
• fuse: Add fuse-io-uring handling into fuse_copy
• fuse: {io-uring} Make hash-list req unique finding functions non-static
• fuse: Add io-uring sqe commit and fetch support
• fuse: {io-uring} Handle teardown of ring entries
• fuse: {io-uring} Make fuse_dev_queue_{interrupt,forget} non-static
• fuse: Allow to queue fg requests through io-uring
• fuse: Allow to queue bg requests through io-uring
• fuse: {io-uring} Prevent mount point hang on fuse-server termination
• fuse: block request allocation until io-uring init is complete
• fuse: enable fuse-over-io-uring
• fuse: prevent disabling io-uring on active connections

Maíra Canal

• drm/vkms: Remove index parameter from init_vkms_output
• drm/vkms: Code formatting
• drm/vkms: Use drm_frame directly
• drm/vkms: Use const for input pointers in pixel_read an pixel_write functions
• drm/v3d: Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL

Tvrtko Ursulin

• drm/etnaviv: Add fdinfo support for memory stats
• drm: make drm-active- stats optional
• Documentation/gpu: Clarify drm memory stats definition
• drm/sched: Fix preprocessor guard

Tested (2)

André Almeida

• ASoC: cs35l41: Fallback to using HID for system_name if no SUB is available

Christian Gmeiner

• hexagon: fix using plain integer as NULL pointer warning in cmpxchg

Acked (1)

Iago Toral Quiroga

• drm/v3d: Fix miscellaneous documentation errors

Maintainer SoB (6)

Maíra Canal

• drm/v3d: Stop active perfmon if it is being destroyed
• drm/v3d: Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL
• drm/vc4: plane: Remove WARN on state being set in plane_reset

Tvrtko Ursulin

• drm/i915: Remove deadcode
• drm/i915: Remove unused intel_huc_suspend
• drm/i915: Remove unused intel_ring_cacheline_align

28 Mar 2025 12:00am GMT

Hi all!

This month I've finally finished my initial work on HDR10 support for wlroots! My branch supports playing both SDR and HDR content on either an SDR or HDR output. It's a pretty basic version: wlroots only performs very basic gamut mapping, and has a simple luminance multiplier instead of proper tone mapping. Additionally the source content luminance and mastering display metadata isn't taken into account. Thus the result isn't as good as it could be, but that can be improved once the initial work is merged!

I've also been talking with dnkl about blending optical color values rather than electrical values in foot ("gamma-correct blending"). Thanks to the color-management protocol, foot can specify that its buffers contain linearly encoded values (as opposed to the default, sRGB) and can implement this blending method without sacrificing performance. See the foot pull request for more details.

We've been working on fixing the few last known blockers remaining for the next wlroots release, in particular related to scene-graph clipping, custom modes, and explicit synchronization. I hope we'll be able to start the release candidate dance soon.

The NPotM is Bakah, a small utility to build Docker Bake configuration files with Buildah (the library powering Podman). I've written more about the motivation and design of this tool in a separate article.

I've released tlstunnel 0.4 with better support for certificate files and some bugfixes. The sogogi WebDAV file server got support for graceful shutdown and Unix socket listeners thanks to Krystian Chachuła. Last, mako 1.10 adds a bunch of useful features such as include directives, more customization for border sizes and icon border radius, and a --no-history flag for makoctl dismiss.

See you next month!

15 Mar 2025 10:00pm GMT

This time I have three topics.

First, I want to promote the blog post I wrote to celebrate the landing of the Wayland color-management extension into wayland-protocols staging area. It's a brief historique of the journey.

Second, I want to discuss SDR and HDR video modes on monitors and TVs. I have seen people expect that the same sRGB content displayed on the SDR video mode and the HDR (BT.2100/PQ) video mode on the same monitor will look the same, and they can arbitrarily switch between the modes at any time. I have argued that this is a false expectation. Why?

Monitors tend to have a slew of settings. I tend to call them monitor "knobs". There are brightness, contrast, color temperature, picture mode, dynamic contrast, sharpness, gamma, and whatever. Many people have noticed that when the video source puts the monitor into BT.2100/PQ video mode, the monitor locks out some settings, often brightness and/or contrast included. So, SDR and HDR video modes do not play by the same rules. Hence, one cannot generally expect a match even if the video source does everything correctly.

Third, there is marketing. Have a look at the first third of this video. They discuss video streaming services, TV selling, and HDR from the picture quality point of view. My take of that is, that (some? most?) monitors and TVs come with a screaming broken picture out-of-the-box because marketing has to sell them. If all displays displayed a given content as intended, they would all look the same, major technology differences notwithstanding, but marketing wants to make each individual stand out.

Have you heard of TV calibration services? If I buy a new TV from a local electronics department store, they offer a calibration service, for a considerable additional fee. Why would anyone need a calibration service, the factory settings should be good, right?

13 Mar 2025 9:40am GMT

11 Mar 2025 4:30pm GMT

New Frontiers

More info

11 Mar 2025 12:00am GMT

Once Again We Return Home

It's been a while, but for the first time this year I have to do it. Some of you are shaking your heads, saying you knew it, and you were right. Here we are again.

It's time to vkoverhead.

The Numbers Must Go Up

I realized while working on some P E R F that there was a lot of perf to be gained in places I wasn't testing. That makes sense, right? If there's no coverage, the perf can't go up.

So I added a new case for the path I was using, and boy howdy did I start to see some weird stuff.

Normally this is where I'd post up some gorgeous flamegraphs, and we would sit back in our expensive leather armchairs debating the finer points of optimization. But you know what? We can't do that anymore.

Why, you're asking. The reason is simple: perf is totally fucking broken and has been for a while. But only on certain machines. Specifically, mine. So no more flamegraphs for you, and none for me.

Despite this massive roadblock, the perf gains must continue. Through the power of guesswork and frustration, I've managed some sizable gains:

Though I was mainly targeting the case of using dynamic vertex input and binding new vertex buffers for every draw (and managed a nearly 100% improvement there) , I ended up seeing noteworthy gains across the board for binding vertex buffers, even when using fully static state. This should provide some minor gains to general RADV perf.

Future Improvements

Given the still-massive perf gap between using static and dynamic vertex state when only vertex buffers change, it seems likely there's still some opportunities to reclaim more perf. Only time will tell what can be achieved here, but for now this is what I've got.

27 Feb 2025 12:00am GMT

Insanity Has A Name

Karol Herbst. At SGC, we know this man. We fear him. His photo is on the wall over a break-in-case-of-emergency glass panel which shields a button activating a subterranean escape route set to implode as soon as I sprint through.

Despite this, and despite all past evidence leading me to be wary of any idea he pitched, the madman got me again.

cl_khr_image2d_from_buffer. On the surface, an innocuous little extension used to access a buffer like a 2D image. Vulkan already has this support for 1D images in the form of VkBufferView, so why would adding a stride to that be any harder (aside from the fact that the API doesn't support it)?

I was deep into otherworldly optimizations at this point, far beyond the point where I was able to differentiate between improvement and neutral, let alone sane or twisted. His words seemed so reasonable: why couldn't I just throw a buffer to the GPU as a 2D image? I'd have to be an idiot not to be able to do something as simple as that. Wouldn't I?

Dammit, Karol.

How to 2D a Buffer

You can't. I mean, I can, but you? Vulkan won't let you do it. There's (currently) no extension that enables a 2D bufferview. Rumor has it some madman on a typewriter is preparing to fax over an extension specification to add this, but only time will tell whether Khronos accepts submissions in this format.

Here at SGC, we're all smart HUMANS though, so there's an obvious solution to this.

It's not memory aliasing. Sure, rebinding buffer memory onto an image might work. But in reading the spec, the synchronization guarantees for buffer-image aliasing didn't seem that strong. And also it'd be a whole bunch of code to track it, and maybe do weird layout stuff, and add some kind of synchronization on the buffer too, and pray the driver isn't buggy, and doesn't this sound a lot like the we-have-this-at-home version of another, better mechanism that zink already has incredible support for?

Yeah. What about these things? How do they wORK?

DMA Buffers: Totally Normal

A DMAbuf is basically a pipe. On one end you have memory. And if you yell TRIANGLE into the other end really loud, something unimaginable and ineffable that lurks deep withinthevoid will slitherand crawl its way up the pipeuntil it GAZES UPON YOU IN YOUR FLESHY MORTAL SHELL ATTEMPTING TO USURP THE POWERS OF THE OLD ONES. It's a fun little experiment with absolutely no unwanted consequences. Try it at home!

The nice thing about dmabufs is I know they work. And I know they work in zink. That's because in order to run an x̸̧̠͓̣̣͎͚̰͎̍̾s̶̡̢͙̞̙͍̬̝̠̩̱̞̮̩̣̑͂͊̎͆̒̓͐͛͊̒͆̄̋ȩ̶̡̨̳̭̲̹̲͎̪̜͒̓̈́̏r̶̩̗͖͙͖̬̟̞̜̠͙̠̎͑̉̌̎̍̑́̏̓̏̒̍͜͝v̶̞̠̰̘̞͖̙̯̩̯̝̂̃̕͜e̴̢̡͎̮͔̤͖̤͙̟̳̹͛̓͌̈̆̈́̽͘̕ŕ̶̫̾͐͘ or a Wayland compositor (e.g., Ŵ̶̢͍̜̙̺͈͉̼̩̯̺̗̰̰͕͍̱͊͊̓̈̀͛̾̒̂̚̕͝ͅḙ̵̛̬̜͔̲͕͖̜̱̻͊̌̾͊͘s̶̢̗̜͈̘͎̠̘̺͉͕̣̯̘̦͓͈̹̻͙̬̘̿͆̏̃̐̍̂̕ͅt̷̨͈̠͕͔̬̙̣͈̪͕̱͕̙̦͕̼̩͙̲͖͉̪̹̼͛̌͋̃̂̂̓̏̂́̔͠͝ͅơ̸̢̛̛̲̟͙͚̰͇̞̖̭̲͍͇̫̘̦̤̩̖͍̄̓́͑̉̿̅̀̉͒͋͒̂́̆̋̚͝ͅͅn̶̢̡̝̥̤̣͔̣͉͖̖̻̬̝̥̦͇͕̘͋͂͛̌̃͠ͅͅ, the reference compositor), dmabufs have to work. Zink can run both of those just fine, so I know there's absolutely zero bugs. There can't be any bugs. No. Not bugs again. NO MORE BUGS

Even better, I know that I can do imports and exports of dmabufs in any dimensionality thanks to that crazy CL-GL sharing extension Karol already suckered me into supporting at the expense of every Vulkan driver's bug tracker. That KAROL HERBST guy, hah, he's such a kidder!

So obviously-It's just common sense at this point-Obviously I should just be able to hook up the pipes here. Export a buffer and then import a 2D image with whatever random CAUSALITY IS A LIE passes for stride. Right? Basically a day at the beach for me.

And of course it works perfectly with no problems whatsoever, giving Davinci Resolve a nice performance boost.

Stay sane, readers.

26 Feb 2025 12:00am GMT

I have been working on getting the camera on the ThinkPad X1 Carbon Gen 12 to work under Fedora.

This requires 3 things:

1. Some ov08x40 sensor patches, these are available as downstream cherry-picks in Fedora kernels >= 6.12.13
2. A small pipewire fix to avoid WirePlumber listing a bunch of bogus extra "ipu6" Video Sources, these fixes are available in Fedora's pipewire packages >= 1.2.7-4
3. I2C and GPIO drivers for the new Lattice USB IO-expander, these drivers are not available in the upstream / mainline kernel yet

I have also rebased the out of tree IPU6 ISP and proprietary userspace stack in rpmfusion and I have integrated the USBIO drivers into the intel-ipu6-kmod package. So for now getting the cameras to work on the X1 Carbon Gen 12 requires installing the out of tree drivers through rpmfusion. Follow these instructions to enable rpmfusion, you need both the free and nonfree repos.

Then make sure you have a new enough kernel installed and install the rpmfusion akmod for the USBIO drivers:

sudo dnf update 'kernel*'
sudo dnf install akmod-intel-ipu6

The latest version of the out of tree IPU6 ISP driver can co-exist with the mainline / upstream IPU6 CSI receiver kernel driver. So both the libcamera software ISP FOSS stack and Intel's proprietary stack can co-exist now. If you do not want to use the proprietary stack you can disable it by running 'sudo ipu6-driver-select foss'.

After installing the kmod package reboot and then in Firefox go to Mozilla's webrtc test page and click on the "Camera" button, you should now get a camera permisson dialog with 2 cameras: "Built in Front Camera" and "Intel MIPI Camera (V4L2)" the "Built in Front Camera" is the FOSS stack and the "Intel MIPI Camera (V4L2)" is the proprietary stack. Note the FOSS stack will show a strongly zoomed in (cropped) image, this is caused by the GUM test-page, in e.g. google-meet this will not be the case.

I have also been making progress with some of the other open IPU6 issues:

• Camera's failing on Dell XPS laptops due to iVSC errors (rhbz#2316918, rhbz#2324683) after a long debugging session this is finally fixed, the fix for this will be available in Fedora kernels >= 6.13.4 which should show up in updates-testing today
• Camera's no working on Microsoft Surface book with ov7251 sensor, the fix for this has landed upstream
  

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24 Feb 2025 2:44pm GMT

Ready in time for libinput 1.28 [1] and after a number of attempts over the years we now finally have 3-finger dragging in libinput. This is a long-requested feature that allows users to drag by using a 3-finger swipe on the touchpad. Instead of the normal swipe gesture you simply get a button down, pointer motion, button up sequence. Without having to tap or physically click and hold a button, so you might be able to see the appeal right there.

Now, as with any interaction that relies on the mere handful of fingers that are on our average user's hand, we are starting to have usage overlaps. Since the only difference between a swipe gesture and a 3-finger drag is in the intention of the user (and we can't detect that yet, stay tuned), 3-finger swipes are disabled when 3-finger dragging is enabled. Otherwise it does fit in quite nicely with the rest of the features we have though.

There really isn't much more to say about the new feature except: It's configurable to work on 4-finger drag too so if you mentally substitute all the threes with fours in this article before re-reading it that would save me having to write another blog post. Thanks.

[1] "soonish" at the time of writing

24 Feb 2025 5:38am GMT

This is a heads up as mutter PR!4292 got merged in time for GNOME 48. It (subtly) changes the behaviour of drag lock on touchpads, but (IMO) very much so for the better. Note that this feature is currently not exposed in GNOME Settings so users will have to set it via e.g. the gsettings commandline tool. I don't expect this change to affect many users.

This is a feature of a feature of a feature, so let's start at the top.

"Tapping" on touchpads refers to the ability to emulate button presses via short touches ("taps") on the touchpad. When enabled, a single-finger tap corresponds emulates a left mouse button click, a two-finger tap a right button click, etc. Taps are short interactions and to be recognised the finger must be set down and released again within a certain time and not move more than a certain distance. Clicking is useful but it's not everything we do with touchpads.

"Tap-and-drag" refers to the ability to keep the pointer down so it's possible to drag something while the mouse button is logically down. The sequence required to do this is a tap immediately followed by the finger down (and held down). This will press the left mouse button so that any finger movement results in a drag. Releasing the finger releases the button. This is convenient but especially on large monitors or for users with different-than-whatever-we-guessed-is-average dexterity this can make it hard to drag something to it's final position - a user may run out of touchpad space before the pointer reaches the destination. For those, the tap-and-drag "drag lock" is useful.

"Drag lock" refers to the ability of keeping the mouse button pressed until "unlocked", even if the finger moves off the touchpads. It's the same sequence as before: tap followed by the finger down and held down. But releasing the finger will not release the mouse button, instead another tap is required to unlock and release the mouse button. The whole sequence thus becomes tap, down, move.... tap with any number of finger releases in between. Sounds (and is) complicated to explain, is quite easy to try and once you're used to it it will feel quite natural.

The above behaviour is the new behaviour which non-coincidentally also matches the macOS behaviour (if you can find the toggle in the settings, good practice for easter eggs!). The previous behaviour used a timeout instead so the mouse button was released automatically if the finger was up after a certain timeout. This was less predictable and caused issues with users who weren't fast enough. The new "sticky" behaviour resolves this issue and is (alanis morissette-stylue ironically) faster to release (a tap can be performed before the previous timeout would've expired).

Anyway, TLDR, a feature that very few people use has changed defaults subtly. Bring out the pitchforks!

As said above, this is currently only accessible via gsettings and the drag-lock behaviour change only takes effect if tapping, tap-and-drag and drag lock are enabled:

  $ gsettings set org.gnome.desktop.peripherals.touchpad tap-to-click true
  $ gsettings set org.gnome.desktop.peripherals.touchpad tap-and-drag true
  $ gsettings set org.gnome.desktop.peripherals.touchpad tap-and-drag-lock true
  

All features above are actually handled by libinput, this is just about a default change in GNOME.

24 Feb 2025 4:17am GMT

For my day job, I need to build and run a Docker Compose project. However, because Docker doesn't play well with nftables and I prefer a rootless + daemonless approach, I'm using Podman.

Podman supports Docker Compose projects with two possible solutions: either by connecting the official Docker Compose CLI to a Podman socket, either by using their own drop-in replacement. They ship a small wrapper to select one of these options. (The wrapper has the same name as the replacement, which makes things confusing.)

Unfortunately, both options have downsides. When using the official Docker Compose CLI, the classic builder is used instead of the newer BuildKit builder. As a result, some features such as additional contexts are not supported. When using the podman-compose replacement, some other features are missing, such as !reset, configs and referencing another service in additional contexts. It would be possible to add these features to podman-compose, but that's an endless stream of work (Docker Compose regularly adds new features) and I don't really see the value in re-implementing all of this (the fact that it's Python doesn't help me getting motivated).

I've started looking for a way to convince the Docker Compose CLI to run under Podman with BuildKit enabled. I've tried a few months ago and never got it to work, but it seems like this recently became easier! The podman-compose wrapper force-disables BuildKit, so we need to use directly the Docker Compose CLI without the wrapper. On Arch Linux, this can be achieved by enabling the Podman socket and creating a new Docker context (same as setting DOCKER_HOST, but more permanent):

pacman -S docker-compose docker-buildx
systemctl --user start podman.socket
docker context create podman --docker host=unix://$XDG_RUNTIME_DIR/podman/podman.sock
docker context use podman

With that, docker compose just works! It turns out it automagically creates a buildx_buildkit_default container under-the-hood to run the BuildKit daemon. Since I don't like automagical things, I immediately tried to run BuildKit daemon myself:

pacman -S buildkit
systemctl --user start buildkit.service
docker buildx create --name local unix://$XDG_RUNTIME_DIR/buildkit/rootless
docker buildx use local

Now docker compose uses our systemd-managed BuildKit service. But we're not done yet! One of the reasons I like Podman is because it's daemonless, and we've got a daemon running in the background. This isn't the end of the world, but it'd be nicer to be able to run the build without BuildKit.

Fortunately, there's a way around this: any Compose project can be turned into a JSON description of the build commands called Bake. docker buildx bake --print will print that JSON file (and the Docker Compose CLI will use Bake files if COMPOSE_BAKE=true is set since v2.33). Note, Bake supports way more features (e.g. HCL files) but we don't really need these for our purposes (and the command above can lower fancy Bake files into dumb JSON ones).

The JSON file is pretty similar to the podman build CLI arguments. It's not that hard to do the translation, so I've written Bakah, a small tool which does exactly this. It uses Buildah instead of shelling out to Podman (Buildah is the library used by Podman under-the-hood to build images). A few details required a bit more attention, for instance dependency resolution and parallel builds, but it's quite simple. It can be used like so:

docker buildx bake --print >bake.json
bakah --file bake.json

Bakah is still missing the fancier Bake features (HCL files, inheritance, merging/overriding files, variables, and so on), but it's enough to build complex Compose projects. I plan to use it for soju-containers in the future, to better split my Dockerfiles (one for the backend, one for the frontend) and remove the CI shell script (which contains a bunch of Podman CLI invocations). I hope it can be useful to you as well!

22 Feb 2025 10:00pm GMT

Busy.

I didn't forget to blog. I know you don't believe me, but I've been accumulating items to blog about for the past month. Powering up. Preparing. And now, finally, it's time to begin opening the valves.

Insanity Returns

When I got back from hibernation, I was immediately accosted by a developer I'd forgotten. One with whom I spent an amount of time consuming adult beverages at XDC again. One who walks with a perpetual glint of madness in his eyes, ready at the drop of a hat to tackle the nearest driver developer and begin raving about the benefits of supporting OpenCL.

Obviously I'm talking about Karol "HOW IS THE PUB ALREADY CLOSED IT'S ONLY 10:30???" Herbst.

I was minding my own business, fixing bugs and addressing perf issues when he assaulted me with a vicious nerdsnipe late one night in January. "Hey, why can't I run DaVinci Resolve on Zink?" he casually asked me, knowing full well the ramifications of such a question.

I tried to put him off, but he persisted. "You know, RadeonSI supports all those features," he said next, and my entire week was ruined. As everyone knows, Zink can only ever be compared to one driver, and the comparisons can't be too uneven.

So it was that I started looking at the CL CTS for the first time this year to implement cl_khr_gl_sharing. This extension is basically EXT_external_objects for CL. It should "just work". Right?

Right…

The thing is, this mechanism (on Linux) uses dmabufs. You know, that thing we all love because they make display servers go vroom. dmabufs allow sharing memory regions between processes through file descriptors. Or just within the same process. Anywhere, really. One side exports the memory object to the FD, and the other side imports it.

But that's how normal people use dmabufs. 2D image import/export for display server usage. Or, occasionally, some crazy multi-process browser engine thing. But still 2D.

You know who uses dmabufs with all-the-Ds? OpenCL.

You know who doesn't implement all-the-Ds? Any Vulkan drivers. Probably. Case in point, I had to hack it in for RADV before I could get CTS to pass and VVL to stop screaming at me.

From there, it turned out zink mostly supported everything already. A minor bugfix and some conditionals to enable raw buffer import/export, and it just works.

Brace yourselves, because this is the foundation for getting Cthulhu-level insane next time.

20 Feb 2025 12:00am GMT

Hi!

This month has been pretty hectic, with FOSDEM and all. I've really enjoyed meeting face-to-face all of these folks I work online with the rest of the year! My talk about modern IRC has been published on the FOSDEM website (unfortunately the audio quality isn't great).

In Wayland news, the color management protocol has finally been merged! I haven't done much apart cheering from the sidelines: huge thanks to everyone involved for carrying this over the finish line, especially Pekka Paalanen, Sebastian Wick and Xaver Hugl! I've started a wlroots implementation, which was enough with some hacks to get MPV to display a HDR video on Sway. I've also posted a patch to convert to BT2020 and encode to PQ, but I still need to figure out why red shows up as pink (or rebrand it as lipstick-filter in the Sway config file).

I've released sway 1.10.1 with a bunch of bugfixes, as well as wlr-randr 0.5.0 which adds relative positioning options (e.g. --left-of) and a man page. I've rewritten makoctl in C (the shell script approach has been showing its limitations for a while), and merged support for icon border radius, per-corner radius settings, and a new signal in the mako-specific D-Bus API to notify when the current modes are changed.

delthas has contributed support for showing redacted messages as such in gamja. goguma's compact mode now displays an unread and date delimiter, just like the default mode (thanks Eigil Skjæveland!). I've added a basic UI to my WebDAV server, sogogi, to display directory listings and easily upload files from the browser.

That's all, see you next month!

17 Feb 2025 10:00pm GMT