[PATCH 3.14 21/98] drm/radeon: properly filter DP1.2 4k modes on non-DP1.2 hw

Greg Kroah-Hartman
2015-01-25T19:18:04Z

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

commit 410cce2a6b82299b46ff316c6384e789ce275ecb upstream.

The check was already in place in the dp mode_valid check, but
radeon_dp_get_dp_link_clock() never returned the high clock
mode_valid was checking for because that function clipped the
clock based on the hw capabilities. Add an explicit check
in the mode_valid function.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=87172

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/radeon/atombios_dp.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -576,6 +576,10 @@ int radeon_dp_mode_valid_helper(struct d
struct radeon_connector_atom_dig *dig_connector;
int dp_clock;

+ if ((mode->clock > 340000) &&
+ (!radeon_connector_is_dp12_capable(connector)))
+ return MODE_CLOCK_HIGH;
+
if (!radeon_connector->con_priv)
return MODE_CLOCK_HIGH;
dig_connector = radeon_connector->con_priv;