Re: i915drmkms debug log issue

[Rui-Xiang Guo <rxg%lavabit.com@localhost>]

Move this to tech-kern@ and tech-toolchain@.

On Tue, Apr 28, 2026 at 07:15:18AM +0000, RVP wrote:
> On Sat, 25 Apr 2026, Rui-Xiang Guo wrote:
> 
> > I'm a bit confused about the DRM debug messages.
> > For example:
> > [   4.6079340] {drm:netbsd:intel_update_max_cdclk+0x8d} Max CD clock rate: 200000 kHz
> > [   4.6179412] {drm:netbsd:intel_modeset_init+0x174f} Max dotclock rate: 360000 kHz
> > 
> > Both DRM_DEBUG_KMS messages exist in intel_update_max_cdclk,
> > but why does the second one show intel_modeset_init?
> > 
> 
> Interesting. You should ask this on tech-kern@ (and I think, tech-toolchain@).
> 
> 1. If you add another `DRM_DEBUG_DRIVER("foo\n");` after the second
>    DRM_DEBUG_DRIVER(), does the first 2 print OK?
> 
> 2. Does adding a plain `printf("foo\n");` after the 2nd DRM_DEBUG_DRIVER() also
>    cause the correct function name to be printed?
> 
> Ie. DRM_DEBUG_DRIVER() (AKA, __drm_dbg()) should not be the last function being
> called.

I test them on NetBSD/amd64 10.0 and the results are:
1.
[   4.5991173] {drm:netbsd:intel_update_max_cdclk+0x8d} Max CD clock rate: 200000 kHz
[   4.5991173] {drm:netbsd:intel_update_max_cdclk+0xa6} Max dotclock rate: 360000 kHz
[   4.6117287] {drm:netbsd:intel_modeset_init+0x174f} test with adding DRM_DEBUG_DRIVER

2.
[   4.5992919] {drm:netbsd:intel_update_max_cdclk+0x8d} Max CD clock rate: 200000 kHz
[   4.5992919] {drm:netbsd:intel_update_max_cdclk+0xa6} Max dotclock rate: 360000 kHz
[   4.6119114] test with adding printf

-rxg