[PATCH v3 1/3] drm: Stop spamming log with drm_cache message

[Lucas De Marchi]

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()

Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---

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);
-- 
2.35.0