Re: kern/50804: Nouveau console doesn't come up on Dell laptop

[Roy Bixler <rcbixler%nyx.net@localhost>]

On Sat, Feb 20, 2016 at 03:55:01PM +0000, Taylor R Campbell wrote:
> The following reply was made to PR kern/50804; it has been noted by GNATS.
> 
> From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
> To: Roy Bixler <rcbixler%nyx.net@localhost>
> Cc: gnats-bugs%NetBSD.org@localhost
> Subject: Re: kern/50804: Nouveau console doesn't come up on Dell laptop
> Date: Sat, 20 Feb 2016 15:51:17 +0000
> 
>     Date: Sat, 20 Feb 2016 08:45:45 -0700
>     From: Roy Bixler <rcbixler%nyx.net@localhost>
>  
>     On Mon, Feb 15, 2016 at 08:41:48PM +0000, Taylor R Campbell wrote:
>     > Another change that might be worthwhile to test would be to add
>     > 
>     > #include <ddb/ddb.h>
>     > 
>     > 	if (bpa/size covers the nvidia bar)
>     > 		db_stack_trace_print(
>     > 		    (db_expr_t)(intptr_t)__builtin_frame_address(0),
>     > 		    true, 65535, "", printf);
>     > 
>     > to bus_space_map in sys/arch/x86/x86/bus_space.c, so that you can see
>     > who is trying to map this bus space, in case someone else has already
>     > mapped it.  (You'll need to fill in what the relevant BAR's address
>     > and size actually are, unless you want to increase MSGBUFSIZE and wade
>     > through a stack trace for every bus space mapping in the system.)
>  
>     The thought occurred to me before, so since you agree, I'll give it a
>     go.
>  
>  Since bus_space_map is apparently failing with EAGAIN, that is
>  definitely worth a try -- EAGAIN means someone else has already mapped
>  some part of the region.

Just one thing here -- I took your latest version and added the debugging
line back in to replay the bus_space_map parameters.  Here's the result:

drm kern info: nouveau  [  DEVICE][nouveau0] BOOT0  : 0x042c00a1
drm kern info: nouveau  [  DEVICE][nouveau0] Chipset: NV42 (NV42)
drm kern info: nouveau  [  DEVICE][nouveau0] Family : NV40
drm kern info: nouveau  [   VBIOS][nouveau0] checking PRAMIN for image...
drm kern info: nouveau  [   VBIOS][nouveau0] ... appears to be valid
drm kern info: nouveau  [   VBIOS][nouveau0] using image from PRAMIN
drm kern info: nouveau  [   VBIOS][nouveau0] BIT signature found
drm kern info: nouveau  [   VBIOS][nouveau0] version 05.41.02.29.a3
drm kern info: nouveau  [     PFB][nouveau0] RAM type: DDR1
drm kern info: nouveau  [     PFB][nouveau0] RAM size: 256 MiB
drm kern info: nouveau  [     PFB][nouveau0]    ZCOMP: 189440 tags
drm kern error: nouveau E[ INSTMEM][nouveau0] bar = 2, iomemt=c1136740, iomemsz=0, start=0
drm kern error: nouveau E[ INSTMEM][nouveau0] unable to map PRAMIN BAR: 35
drm kern error: nouveau E[  DEVICE][nouveau0] failed to create 0x1000400c, -14
drm kern error: nouveau E[     DRM] failed to create 0x80000080, -14
nouveau0: unable to attach drm: 14

So, the size and start of 0 definitely seem wrong.  I suppose I'll try
my experiment with bar = 1.

-- 
Roy Bixler <rcbixler%nyx.net@localhost>
"The fundamental principle of science, the definition almost, is this: the
sole test of the validity of any idea is experiment."
-- Richard P. Feynman