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.
>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
> ---
>
> v3: No changes from previous version, just submitting to the right
> mailing list
>
> drivers/gpu/drm/drm_cache.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
> index f19d9acbe959..2c3fa5677f7e 100644
> --- a/drivers/gpu/drm/drm_cache.c
> +++ b/drivers/gpu/drm/drm_cache.c
> @@ -112,8 +112,7 @@ drm_clflush_pages(struct page *pages[], unsigned long num_pages)
> kunmap_atomic(page_virtual);
> }
> #else
> - pr_err("Architecture has no drm_cache.c support\n");
> - WARN_ON_ONCE(1);
> + WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
> #endif
> }
> EXPORT_SYMBOL(drm_clflush_pages);
> @@ -143,8 +142,7 @@ drm_clflush_sg(struct sg_table *st)
> if (wbinvd_on_all_cpus())
> pr_err("Timed out waiting for cache flush\n");
> #else
> - pr_err("Architecture has no drm_cache.c support\n");
> - WARN_ON_ONCE(1);
> + WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
> #endif
> }
> EXPORT_SYMBOL(drm_clflush_sg);
> @@ -177,8 +175,7 @@ drm_clflush_virt_range(void *addr, unsigned long length)
> if (wbinvd_on_all_cpus())
> pr_err("Timed out waiting for cache flush\n");
> #else
> - pr_err("Architecture has no drm_cache.c support\n");
> - WARN_ON_ONCE(1);
> + WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
> #endif
> }
> EXPORT_SYMBOL(drm_clflush_virt_range);
