Message-ID: <fd78534e597c904ee3440782dd5e4442@3xo.fr>
Date: Fri, 14 Feb 2025 16:10:54 +0100
From: Nicolas Baranger <nicolas.baranger@....fr>
To: Thomas Zimmermann <tzimmermann@...e.de>
Cc: Jocelyn Falempe <jfalempe@...hat.com>, dri-devel@...ts.freedesktop.org,
 airlied@...hat.com, Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, David Airlie <airlied@...il.com>, Simona
 Vetter <simona@...ll.ch>, linux-kernel@...r.kernel.org
Subject: Re: Include ASPEED ast-drm 1.15.1 video driver in kernel tree

Hi Thomas

> We're not going to merge a second driver for hardware we already 
> support. The upstream kernel's driver is the one we should improve. I'm 
> glad for the bug report and information you already provided. If you 
> want to help with further testing and, you're welcome to do so.

Sure I understand !
No problems to continue testing or whatever could help

Thanks again
Kind regards
Nicolas Baranger


Le 2025-02-14 13:46, Thomas Zimmermann a écrit :

> Hi
> 
> Am 14.02.25 um 13:09 schrieb Nicolas Baranger:
> 
>> Dear Jocelyn
>> 
>> Thanks for answer and help
>> 
>> Ok, I will try linux 6.1 (could you confirm that every commit in 6.1 
>> before 965361 should be relevant ?)
>> 
>> If I need to have "~correct or better to say 'acceptable' year 2025 
>> performances~" on AST2400 VGA card it's because at the hardware level 
>> if I select the NVIDIA discrete GPU as the main server video output, I 
>> lost all the server management benefits and capabilities of the 
>> AST2400 BMC (except PSU management) as I get a black screen... And 
>> it's dangerous as keyboard and mouse keep working on the black screen 
>> and so, can launch destructive actions without knowing it !
>> 
>> Also I'm still surprise by Thomas answer as the aspeed drm drivers 
>> 1.15.1 is dated of December 2024...
> 
> Well, I cannot find a difference except for the old memory management. 
> Aspeed has meanwhile also contributed patches to the upstream kernel. 
> They might cover some of the differences. I also noticed that the 
> Aspeed driver for v6.6 seems to use the newer memory management.
> 
>> And Jammy Huang from AspeedTech teold me to contact here to upstream 
>> the ast_new adaptation I've made after he knows that I did version 
>> 1.15.1 work on mainline (Aspeed only support LTS kernel and their dkms 
>> package were not usable out-of-the-box on mainline)
>> 
>> I may surely be wrong and some explanations could help me to 
>> understand which is the actual situation of ast driver in kernel tree.
> 
> We're not going to merge a second driver for hardware we already 
> support. The upstream kernel's driver is the one we should improve. I'm 
> glad for the bug report and information you already provided. If you 
> want to help with further testing and, you're welcome to do so.
> 
> Best regards
> Thomas
> 
> I would let you know the results in 6.1
> 
> Again thanks a lot for help !
> 
> Kind regards,
> Nicolas Baranger
> 
> -------- Message d'origine --------
> De : Jocelyn Falempe <jfalempe@...hat.com>
> Date : 14/02/2025 10:11 (GMT+01:00)
> À : Nicolas Baranger <nicolas.baranger@....fr>, Thomas Zimmermann 
> <tzimmermann@...e.de>
> Cc : dri-devel@...ts.freedesktop.org, airlied@...hat.com, Maarten 
> Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard 
> <mripard@...nel.org>, David Airlie <airlied@...il.com>, Simona Vetter 
> <simona@...ll.ch>, linux-kernel@...r.kernel.org
> Objet : Re: Include ASPEED ast-drm 1.15.1 video driver in kernel tree
> 
> On 13/02/2025 10:27, Nicolas Baranger wrote: Dear Thomas
> 
> Thanks for answer and help.
> 
> Yes, due to .date total removal in linux 6.14 (https://github.com/
> torvalds/linux/commit/cb2e1c2136f71618142557ceca3a8802e87a44cd 
> <https://
> github.com/torvalds/linux/commit/
> cb2e1c2136f71618142557ceca3a8802e87a44cd>) the last DKMS sources are :
> https://xba.soartist.net/ast-drm_nba_20250211/nba-dkms/
> nba_last_src_20250212/src/ <https://xba.soartist.net/ast-
> drm_nba_20250211/nba-dkms/nba_last_src_20250212/src/>
> 
> You can also find this sources in directory drivers/gpu/drm/ast_new of
> the tarball https://xba.soartist.net/ast-drm_nba_20250211/nba-kernel/
> linux-6.14.0.1-ast1.15.1-rc2_nba0_20250212.tar.gz <https://
> xba.soartist.net/ast-drm_nba_20250211/nba-kernel/linux-6.14.0.1-
> ast1.15.1-rc2_nba0_20250212.tar.gz>
> 
> I'm surprised by the fact the in-kernel driver 0.1.0 is more advanced
> than Aspeed version 1.15.1 because on my system it has very poor
> rendering and is very slow, twinkle is high and had poor colors.
> The screen flickering is high and it's like if I was using a very old
> cathode ray tube monitor (In fact I'm using a SAMSUNG LCD monitor which
> is perfectly functionnal and which display a nice and eyes confortable
> picture when using ast 1.15.1 driver or the video output of the Nvidia
> GPU ).
> 
> My testing system is a test Xeon server with an AST2400 BMC with its 
> AST
> VGA card as the main video output (to be able to have a screen on the
> BMC KVM) +a discrete NVIDIA GPU I'm using for GPGPU and 3D rendering
> with Nvidia prime render offload.
> What I constat with embed kernel driver 0.1.0 is that the Xeon 
> processor
> is doing the video job for example when watching a video, and it's not
> the case with version 1.15.1 even when displaying on the AST VGA card a
> vulkan rotating cube (compute by nvidia GPU with nvidia prime but
> display by the AST VGA card of the AST2400).
> Note that with in-kernel version 0.1.0 it's nearly impossible to make
> round the vulkan cube at more than half a round by  second where it's
> working (very) fine for a 32MB video memory card with version 1.15.1 as
> you can see in the video present in the online directory
> 
> I'm not developer or kernel developer so be sure that I wouldn't have
> done all this work if the in-kernel ast version 0.1.0 was usable 
> out-of-
> the-box
> 
> Sure you can give me a patch I will test on this server (building
> mainline+ast_new yesterday tooks 19 minutes on this server)
> 
> PS:
> here is a 'git diff linux-6.14.0.1-ast-rc2/drivers/gpu/drm/ast
> linux-6.14.0.1-ast-rc2/drivers/gpu/drm/ast_new'
> https://xba.soartist.net/ast-drm_nba_20250211/nba-dump/ast-
> fullpatch.patch 
> <https://xba.soartist.net/ast-drm_nba_20250211/nba-dump/
> ast-fullpatch.patch>
> Diff is about 250+ kb so the 2 drivers seems to have nothing to do with
> each others...
> 
> Thanks again for help
> 
> Kind regards
> Nicolas
> 
> Le 2025-02-13 08:57, Thomas Zimmermann a écrit :
> 
> Hi Nicolas
> 
> Am 12.02.25 um 19:58 schrieb Nicolas Baranger: Dear maintener
> That's mostly me and Jocelyn.
> 
> I did include ast-drm driver version 1.15.1 (in replacement of
> version 0.1.0) on the new mainline kernel too (6.14.0-rc2) and I
> issue a new dkms patch
> 
> Last DKMS patch had been sucessfully tested on mainline.
> And last ast.ko version 1.15.1 included in linux tree had also been
> sucessfully tested
> 
> Online directory is updated with :
> - new DKMS patch
> - new DKMS srouces
> - new DKMS debian package
> - new tarball of mainline included ast_new ported in kernel tree
> - new kernel debian package (mainline with ast_new)
> 
> NB: online directory is here: https://xba.soartist.net/ast-
> drm_nba_20250211/ <https://xba.soartist.net/ast-drm_nba_20250211/>
> 
> Please let me know what I should do to see this change in linux-next
> I'm having a little trouble with figuring out which of the many driver
> sources is the relevant one. Am I correct to assume it's the one at
> 
> https://xba.soartist.net/ast-drm_nba_20250211/nba-dkms/
> nba_last_src_20250212/src/ <https://xba.soartist.net/ast-
> drm_nba_20250211/nba-dkms/nba_last_src_20250212/src/>
> 
> About that driver: Although the official driver reports an ancient
> version number, it is an up-to-date driver. It is actually more up-to-
> date than Aspeed's package. Both drivers share source code and a few
> years ago there was an effort to bring the kernel's driver up to the
> same feature set. Since then, the kernel's driver has been updated,
> reworked and improved.
> 
> About the performance: From what I can tell, the only significant
> difference in these drivers is memory management. Your ast_new driver
> uses an older algorithm that we replaced quite a few releases ago. The
> old version was unreliable on systems with little video memory, so we
> had to replace it.  I don't know why the new code should be slower 
> though.

Regarding the performances of ast driver, I remember doing profiling
some times ago, and when running glxgears (with llvmpipe), 65% of the
CPU time was wasted in page fault
(https://elixir.bootlin.com/linux/v6.13.2/source/drivers/gpu/drm/drm_gem_shmem_helper.c#L534)
But as this driver is mostly used for console/basic desktop usage, I
didn't investigate more.

If I remember correctly, the switch to shmem, is because some devices
have only 16MB of memory, and 1920x1200x32bits takes ~9MB, so it's not
possible to have double buffering in this case. (And this is required by
most desktop environment).

The switch to shmem was done with "f2fa5a99ca81c drm/ast: Convert ast to
SHMEM", and introduced in v6.2. So maybe if you can try with a v6.1
kernel, using the built-in ast driver and report if it has better
performances.

Best regards,

-- Jocelyn

> If I give you a patch against a recent Linux kernel, are you capable
> of building the patched kernel and testing that change on your system?
> 
> Best regards
> Thomas
> 
> Thanks for help
> 
> Kind regards
> Nicolas Baranger
> 
> Le 2025-02-11 19:15, Nicolas Baranger a écrit :
> 
> Dear maintener
> 
> For my own usage, I did make work the ASPEED ast-drm 1.15.1 video
> driver on mainline kernel (6.13.0 + 6.13.1).
> 
> ASPEED video driver is availiable here:
> https://www.aspeedtech.com/file/support/Linux_DRM_1.15.1_4.tar.gz
> <https://www.aspeedtech.com/file/support/Linux_DRM_1.15.1_4.tar.gz>
> 
> But it only work for LTS kernel
> So I modify the DKMS package and I build a new Debian DKMS package
> with the adapted  source.
> My patch can be find here :
> https://xba.soartist.net/ast-drm_nba_20250211/nba-dkms/astdiff.patch
> <https://xba.soartist.net/ast-drm_nba_20250211/nba-dkms/astdiff.patch>
> See the README:
> https://xba.soartist.net/ast-drm_nba_20250211/nba-dkms/README
> <https://xba.soartist.net/ast-drm_nba_20250211/nba-dkms/README>
> 
> Using this new 'ast 1.15.1' driver, performance are amazing compared
> to the 'ast' driver include in kernel tree, specially when using a
> discrete GPU and offloading VULKAN / 3D on it but using AST VGA card
> as the main video card and as the main and only video output (the
> discrete GPU is used only for offloading 3D or for cuda/opencl)
> 
> So to make things easier, I include the new 'ast 1.15.1' driver in
> kernel tree as AST_NEW : linux-6.13.1-ast/drivers/gpu/drm/ast_new'
> It's working fine as you can see on this video :
> https://xba.soartist.net/ast-drm_nba_20250211/
> vulcan_nvidia_prime_render_offload_on_ast_vga_card.webm <https://
> xba.soartist.net/ast-drm_nba_20250211/
> vulcan_nvidia_prime_render_offload_on_ast_vga_card.webm> I upload
> all the work I've done here :
> https://xba.soartist.net/ast-drm_nba_20250211/ <https://
> xba.soartist.net/ast-drm_nba_20250211/>
> 
> See the global README :
> https://xba.soartist.net/ast-drm_nba_20250211/README <https://
> xba.soartist.net/ast-drm_nba_20250211/README>
> 
> and the README in nba-kernel sub-directory :
> https://xba.soartist.net/ast-drm_nba_20250211/nba-kernel/README
> <https://xba.soartist.net/ast-drm_nba_20250211/nba-kernel/README>
> 
> I'm not a developer so please let me know if I made the things the
> right way and if this new 'ast 1.15.1' driver can be ported to
> linux-next or linux-? ?
> If you need more explanations, do not hesitate to contact me, I
> would be happy to help
> 
> Kind regards
> Nicolas Baranger

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