re: xsrc/56729 (amdgpu X driver nearly (but not quite) working)

[matthew green <mrg%eterna.com.au@localhost>]

The following reply was made to PR xsrc/56729; it has been noted by GNATS.

From: matthew green <mrg%eterna.com.au@localhost>
To: xsrc-manager%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost,
    gnats-admin%netbsd.org@localhost, riastradh%NetBSD.org@localhost, martin%NetBSD.org@localhost,
    gnats-bugs%netbsd.org@localhost
Cc: 
Subject: re: xsrc/56729 (amdgpu X driver nearly (but not quite) working)
Date: Fri, 16 Sep 2022 17:26:05 +1000

 > i booted amdgpu (RX550) on a recent -current system and the
 > system hard hung when starting X11.  serial break does not
 > give me ddb...
 
 this turns out to be some unrelated issue.  i didn't have
 amdgpu in my kernel at all (so this was vga0 attached,
 and then something else hard hanging starting X.)
 
 i'm able to run some basic stuff and it works fine, but
 an issue i had a while back remains, if slightly different
 in nature.
 
 if i run 'mpv' in full-screen mode, the display becomes
 corrupted in a wrong-palette-like way, but with damaged
 interfaces that may have apps behind the foreground app
 mixed in some how (eg, glxgears data.)  in the background
 it seems that a ring becomes locked up and the drm tries
 to reset, but ultimately ends up not working (you get
 errors trying to initialise a parser after it claims
 to succeed.)
 
 the host survives a while without doing mpv in full screen.
 
 you can see an example of the reset issue being triggered
 twice in:
    https://github.com/riastradh/netbsd-src/issues/28
 
 the mpv above exited, and i attempted to run another one,
 which gave me eg:
 
 amdgpu: amdgpu_cs_query_fence_status failed.
 amdgpu: The CS has been cancelled because the context is lost.
 amdgpu: The CS has been cancelled because the context is lost.
 
 messages from libdrm_amdgpu, and did nothing, so i ^C'd
 it which turned it into a zombie.  crash shows this BT:
 
 crash> bt/a ffff82ea1303a140
 trace: pid 2000 lid 4093 at 0xffff8710b95be9b0
 sleepq_block() at sleepq_block+0x13a
 cv_wait() at cv_wait+0x49
 linux_dma_fence_default_wait() at linux_dma_fence_default_wait+0x163
 linux_dma_fence_wait_timeout() at linux_dma_fence_wait_timeout+0xde
 linux_dma_fence_wait() at linux_dma_fence_wait+0x52
 amdgpu_vm_fini() at amdgpu_vm_fini+0xa9
 amdgpu_driver_postclose_kms() at amdgpu_driver_postclose_kms+0x133
 drm_file_free() at drm_file_free+0x1a8
 drm_close() at drm_close+0x60
 closef() at closef+0x60
 fd_free() at fd_free+0x1e4
 exit1() at exit1+0x13e
 sigexit() at sigexit+0x2e7
 postsig() at sendsig
 lwp_userret() at lwp_userret+0x20a
 mi_userret() at mi_userret+0x249
 syscall() at syscall+0x116
 --- syscall (number 4) ---
 syscall+0x116:
 crash>