[PATCH] drm/radeon: avoid printing NULL strings

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

gcc-10 warns about some printf format strings that are used to
unconditionally print a NULL string pointer from some call
sites:

In function 'evergreen_surface_check',
    inlined from 'evergreen_cs_track_validate_stencil' at drivers/gpu/drm/radeon/evergreen_cs.c:592:6,
    inlined from 'evergreen_cs_track_check' at drivers/gpu/drm/radeon/evergreen_cs.c:995:8:
include/linux/dev_printk.h:156:24: error: '%s' directive argument is null [-Werror=format-overflow=]
  156 |  dev_printk_index_wrap(_dev_warn, KERN_WARNING, dev, dev_fmt(fmt), ##__VA_ARGS__)

This is harmless here because the kernel prints them as "(null)", but
still breaks the build when compiling with -Werror.

Pass empty strings instead to avoid these warnings.

Fixes: 285484e2d55e ("drm/radeon: add support for evergreen/ni tiling informations v11")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/radeon/evergreen_cs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/radeon/evergreen_cs.c b/drivers/gpu/drm/radeon/evergreen_cs.c
index daaeae6ba141..550e8f35c7d2 100644
--- a/drivers/gpu/drm/radeon/evergreen_cs.c
+++ b/drivers/gpu/drm/radeon/evergreen_cs.c
@@ -589,7 +589,7 @@ static int evergreen_cs_track_validate_stencil(struct radeon_cs_parser *p)
 		return r;
 	}
 
-	r = evergreen_surface_check(p, &surf, NULL);
+	r = evergreen_surface_check(p, &surf, "");
 	if (r) {
 		/* old userspace doesn't compute proper depth/stencil alignment
 		 * check that alignment against a bigger byte per elements and
@@ -818,7 +818,7 @@ static int evergreen_cs_track_validate_texture(struct radeon_cs_parser *p,
 	}
 
 	/* align height */
-	evergreen_surface_check(p, &surf, NULL);
+	evergreen_surface_check(p, &surf, "");
 	surf.nby = ALIGN(surf.nby, surf.halign);
 
 	r = evergreen_surface_check(p, &surf, "texture");
@@ -881,7 +881,7 @@ static int evergreen_cs_track_validate_texture(struct radeon_cs_parser *p,
 				surf.mode = ARRAY_1D_TILED_THIN1;
 			}
 			/* recompute alignment */
-			evergreen_surface_check(p, &surf, NULL);
+			evergreen_surface_check(p, &surf, "");
 			break;
 		case ARRAY_LINEAR_GENERAL:
 		case ARRAY_LINEAR_ALIGNED:
-- 
2.39.5