[Intel-xe] [PATCH] drm/xe: Prevent flooding the kernel log with XE_IOCTL_ERR

[Lucas De Marchi]

On Thu, May 25, 2023 at 04:16:43PM +0000, Francois Dugast wrote:
>Lower log level of XE_IOCTL_ERR macro to debug in order to prevent
>flooding kernel log. Rely on drm_dbg macro output which includes
>function name, so removing file and name macros.
>
>Reported-by: Oded Gabbay <ogabbay at kernel.org>
>Link: https://lists.freedesktop.org/archives/intel-xe/2023-May/004704.html
>Signed-off-by: Francois Dugast <francois.dugast at intel.com>
>---
> drivers/gpu/drm/xe/xe_macros.h | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_macros.h b/drivers/gpu/drm/xe/xe_macros.h
>index 0d24c124d202..2b8a46ffb93e 100644
>--- a/drivers/gpu/drm/xe/xe_macros.h
>+++ b/drivers/gpu/drm/xe/xe_macros.h
>@@ -13,8 +13,8 @@
> #define XE_BUG_ON BUG_ON
>
> #define XE_IOCTL_ERR(xe, cond) \

		   ^^^

>-	((cond) && (drm_info(&(xe)->drm, \
>-			    "Ioctl argument check failed at %s:%d: %s", \
>-			    __FILE__, __LINE__, #cond), 1))
>+	((cond) && (drm_dbg(&(xe)->drm, \

			^^^

now you have a mismatch.

 From a quick look we already have
several places with mixed usage. See e.g. engine_set_timeslice(),
engine_set_preemption_timeout(), engine_set_priority(). There are also a
few places that will log on ENOMEM, which should not be there, but is
not caught by checkpatch since it's obfuscated in the macro (see
scripts/checkpatch.pl - "# check for unnecessary "Out of Memory"
messages")

Can we get away simply removing it?  retsnoop is a thing nowadays and to
understand where the error is coming from, userspace could simply run it
on the side... something like

	# ./retsnoop -e '*sys_ioctl' -a ':drivers/gpu/drm/xe/*.c'

which returns more useful things if the error is farther down the
call stack.

Lucas De Marchi

>+			    "Ioctl argument check failed: %s", \
>+			    #cond), 1))
>
> #endif
>-- 
>2.34.1
>