Re: [PATCH] drm/ttm: fix error handling in ttm_bo_handle_move_mem()

[Dan Carpenter <dan.carpenter@oracle.com>]

On Wed, Jun 16, 2021 at 01:00:38PM +0200, Christian König wrote:
> 
> 
> Am 16.06.21 um 11:36 schrieb Dan Carpenter:
> > On Wed, Jun 16, 2021 at 10:47:14AM +0200, Christian König wrote:
> > > 
> > > Am 16.06.21 um 10:37 schrieb Dan Carpenter:
> > > > On Wed, Jun 16, 2021 at 08:46:33AM +0200, Christian König wrote:
> > > > > Sending the first message didn't worked, so let's try again.
> > > > > 
> > > > > Am 16.06.21 um 08:30 schrieb Dan Carpenter:
> > > > > > There are three bugs here:
> > > > > > 1) We need to call unpopulate() if ttm_tt_populate() succeeds.
> > > > > > 2) The "new_man = ttm_manager_type(bdev, bo->mem.mem_type);" assignment
> > > > > >       was wrong and it was really assigning "new_mem = old_mem;".  There
> > > > > >       is no need for this assignment anyway as we already have the value
> > > > > >       for "new_mem".
> > > > > > 3) The (!new_man->use_tt) condition is reversed.
> > > > > > 
> > > > > > Fixes: ba4e7d973dd0 ("drm: Add the TTM GPU memory manager subsystem.")
> > > > > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > > > > ---
> > > > > > This is from reading the code and I can't swear that I have understood
> > > > > > it correctly.  My nouveau driver is currently unusable and this patch
> > > > > > has not helped.  But hopefully if I fix enough bugs eventually it will
> > > > > > start to work.
> > > > > Well NAK, the code previously looked quite well and you are breaking it now.
> > > > > 
> > > > > What's the problem with nouveau?
> > > > > 
> > > > The new Firefox seems to excersize nouveau more than the old one so
> > > > when I start 10 firefox windows it just hangs the graphics.
> > > > 
> > > > I've added debug code and it seems like the problem is that
> > > > nv50_mem_new() is failing.
> > > Sounds like it is running out of memory to me.
> > > 
> > > Do you have a dmesg?
> > > 
> > At first there was a very straight forward use after free bug which I
> > fixed.
> > https://lore.kernel.org/nouveau/YMinJwpIei9n1Pn1@mwanda/T/#u
> > 
> > But now the use after free is gone the only thing in dmesg is:
> > "[TTM] Buffer eviction failed".  And I have some firmware missing.
> > 
> > [  205.489763] rfkill: input handler disabled
> > [  205.678292] nouveau 0000:01:00.0: Direct firmware load for nouveau/nva8_fuc084 failed with error -2
> > [  205.678300] nouveau 0000:01:00.0: Direct firmware load for nouveau/nva8_fuc084d failed with error -2
> > [  205.678302] nouveau 0000:01:00.0: msvld: unable to load firmware data
> > [  205.678304] nouveau 0000:01:00.0: msvld: init failed, -19
> > [  296.150632] [TTM] Buffer eviction failed
> > [  417.084265] [TTM] Buffer eviction failed
> > [  447.295961] [TTM] Buffer eviction failed
> > [  510.800231] [TTM] Buffer eviction failed
> > [  556.101384] [TTM] Buffer eviction failed
> > [  616.495790] [TTM] Buffer eviction failed
> > [  692.014007] [TTM] Buffer eviction failed
> > 
> > The eviction failed message only shows up a minute after the hang so it
> > seems more like a symptom than a root cause.
> 
> Yeah, look at the timing. What happens is that the buffer eviction timed out
> because the hardware is locked up.
> 
> No idea what that could be. It might not even be kernel related at all.

I don't think it's hardware related...  Using an old version of firefox
"fixes" the problem.  I downloaded the firmware so that's not the issue.
Here's the dmesg load info with the new firmware.

[    1.412458] AMD-Vi: AMD IOMMUv2 driver by Joerg Roedel <jroedel@suse.de>
[    1.412527] AMD-Vi: AMD IOMMUv2 functionality not available on this system
[    1.412710] nouveau 0000:01:00.0: vgaarb: deactivate vga console
[    1.417213] Console: switching to colour dummy device 80x25
[    1.417272] nouveau 0000:01:00.0: NVIDIA GT218 (0a8280b1)
[    1.531565] nouveau 0000:01:00.0: bios: nvkm_bios_new: version 70.18.6f.00.05
[    1.531916] nouveau 0000:01:00.0: fb: nvkm_ram_ctor: 1024 MiB DDR3
[    2.248212] tsc: Refined TSC clocksource calibration: 3392.144 MHz
[    2.248218] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x30e5517d4e4, max_idle_ns: 440795261668 ns
[    2.252203] clocksource: Switched to clocksource tsc
[    2.848138] nouveau 0000:01:00.0: DRM: VRAM: 1024 MiB
[    2.848142] nouveau 0000:01:00.0: DRM: GART: 1048576 MiB
[    2.848145] nouveau 0000:01:00.0: DRM: TMDS table version 2.0
[    2.848147] nouveau 0000:01:00.0: DRM: DCB version 4.0
[    2.848149] nouveau 0000:01:00.0: DRM: DCB outp 00: 01000302 00020030
[    2.848151] nouveau 0000:01:00.0: DRM: DCB outp 01: 02000300 00000000
[    2.848154] nouveau 0000:01:00.0: DRM: DCB outp 02: 02011362 00020010
[    2.848155] nouveau 0000:01:00.0: DRM: DCB outp 03: 01022310 00000000
[    2.848157] nouveau 0000:01:00.0: DRM: DCB conn 00: 00001030
[    2.848159] nouveau 0000:01:00.0: DRM: DCB conn 01: 00002161
[    2.848161] nouveau 0000:01:00.0: DRM: DCB conn 02: 00000200
[    2.850214] nouveau 0000:01:00.0: DRM: MM: using COPY for buffer copies
[    2.908409] nouveau 0000:01:00.0: DRM: allocated 1600x900 fb: 0x70000, bo 00000000091fb080
[    2.908518] fbcon: nouveaudrmfb (fb0) is primary device
[    2.955528] Console: switching to colour frame buffer device 200x56
[    2.957780] nouveau 0000:01:00.0: [drm] fb0: nouveaudrmfb frame buffer device
[    2.957926] [drm] Initialized nouveau 1.3.1 20120801 for 0000:01:00.0 on minor 0
[    2.959816] loop: module loaded

regards,
dan carpenter