[PATCH 3.4 053/107] drm/radeon/combios: add some validation of lvds values

lizf
2016-03-16T08:10:10Z

From: Alex Deucher <alexander.deucher@amd.com>

3.4.111-rc1 review patch. If anyone has any objections, please let me know.

------------------

commit 0a90a0cff9f429f886f423967ae053150dce9259 upstream.

Fixes a broken hsync start value uncovered by:
abc0b1447d4974963548777a5ba4a4457c82c426
(drm: Perform basic sanity checks on probed modes)

The driver handled the bad hsync start elsewhere, but
the above commit prevented it from getting added.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=91401

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
drivers/gpu/drm/radeon/radeon_combios.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index cf5dd63..b72eb50 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -1259,10 +1259,15 @@ struct radeon_encoder_lvds *radeon_combios_get_lvds_info(struct radeon_encoder

if ((RBIOS16(tmp) == lvds->native_mode.hdisplay) &&
(RBIOS16(tmp + 2) == lvds->native_mode.vdisplay)) {
+ u32 hss = (RBIOS16(tmp + 21) - RBIOS16(tmp + 19) - 1) * 8;
+
+ if (hss > lvds->native_mode.hdisplay)
+ hss = (10 - 1) * 8;
+
lvds->native_mode.htotal = lvds->native_mode.hdisplay +
(RBIOS16(tmp + 17) - RBIOS16(tmp + 19)) * 8;
lvds->native_mode.hsync_start = lvds->native_mode.hdisplay +
- (RBIOS16(tmp + 21) - RBIOS16(tmp + 19) - 1) * 8;
+ hss;
lvds->native_mode.hsync_end = lvds->native_mode.hsync_start +
(RBIOS8(tmp + 23) * 8);

--
1.9.1