re: port-i386/53364: System crashes soon after X server is started with viadrm driver

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

The following reply was made to PR port-i386/53364; it has been noted by GNATS.

From: matthew green <mrg%eterna.com.au@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: port-i386-maintainer%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
    netbsd-bugs%netbsd.org@localhost
Subject: re: port-i386/53364: System crashes soon after X server is started with viadrm driver 
Date: Fri, 15 Jun 2018 06:58:13 +1000

 > trap type 6 code 0 eip 0xc08486e6 cs 0x8 eflags 0x13286 cr2 0xfffffffc i=
 level 0 esp 0xdbde5c60
 
 -> cr2 0xfffffffc
 
 this is a pointer of -4 that faulted.  i wonder if something
 is usingo container_of() on a NULL pointer, but i don't see
 anything that would do this in viadrm code.
 
 > mutex_oncpu.part.0(c37af114,0,ea000000,0,c0e2cda4,dbde5c68,0,0,dbde5c4c,=
 c01386f6) at netbsd:mutex_oncpu.part.0+0x6
 > mutex_vector_enter(c3641dc4,200000,c3632000,c3588400,dbde5c8c,c0716e3c,1=
 ,dee80000,200000,dbde5c9c) at netbsd:mutex_vector_enter+0x98
 > via_dma_blit(c3588400,dbde5eac,c4430134,9000,0,1140010,db55c000,c2f379e4=
 ,1,4e) at netbsd:via_dma_blit+0x58
 [ ... ]
 > #7  0xc0848813 in mutex_vector_enter ()
 > #8  0xc071a7be in via_dma_blit ()
 > #9  0xc07141ff in drm_ioctl ()
 
 can you build a kernel with makeoptions DEBUG=3D"-g" and then inspect
 the "blitq" variable in via_dma_blit()?
 
 thanks.
 
 
 .mrg.