From 8a89e5ae76d09b504b785ca3f3405406a6065c97 Mon Sep 17 00:00:00 2001
From: Lucas De Marchi <lucas.demarchi@intel.com>
Date: Mon, 31 Jan 2022 08:59:24 -0800
Subject: drm: Stop spamming log with drm_cache message
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Git-commit: 9277b75675113d64a74ec01a1219973f3720d9a7
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

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@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220131165926.3230642-2-lucas.demarchi@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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 ebff6bf811a5..7051c9c909c2 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);
-- 
2.38.1