On Tue, Feb 01, 2022 at 09:12:05AM -0800, Jose Souza wrote:
On Mon, 2022-01-31 at 08:59 -0800, Lucas De Marchi wrote:
Only x86 and in some cases PPC have support added in drm_cache.c for the
clflush class of functions. However warning once is sufficient to taint
the log instead of spamming it with "Architecture has no drm_cache.c
support" every few millisecond. Switch to WARN_ONCE() so we still get
the log message, but only once, together with the warning. E.g:
------------[ cut here ]------------
Architecture has no drm_cache.c support
WARNING: CPU: 80 PID: 888 at drivers/gpu/drm/drm_cache.c:139 drm_clflush_sg+0x40/0x50 [drm]
...
v2 (Jani): use WARN_ONCE() and keep the message previously on pr_err()
Reviewed-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
But while at it, why not add a drm_device parameter to this function so we can use drm_WARN_ONCE()?
Anyways, it is better than before.
I thought about that, but it didn't seem justifiable because:
1) drm_WARN_ONCE will basically add dev_driver_string() to the log.
However the warning message here is basically helping the bootstrap of
additional archs. They shouldn't be seen on anything properly supported.
2) This seems all to be a layer below drm anyway and could even be used
in places outside easy access to a drm pointer.
So, it seems the benefit of using the subsystem-specific drm_WARN_ONCE
doesn't justify the hassle of changing the callers, possibly adding
additional back pointers to have access to the drm device pointer.
thanks
Lucas De Marchi
