drm/i915/dp: read sink count to a temporary variable first

Don't clobber intel_dp->sink_count with the raw value.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/37d3222115172922fcd5ab038238359935bd561f.1491485983.git.jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 81682fd2804b393180871be9138e5ac1eb00f5e2..3c5c80da9ea38f4bdb09ced01ad5c5937270b919 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3728,6 +3728,8 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
 static bool
 intel_dp_get_dpcd(struct intel_dp *intel_dp)
 {
+       u8 sink_count;
+
        if (!intel_dp_read_dpcd(intel_dp))
                return false;
 
@@ -3737,8 +3739,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
                intel_dp_set_common_rates(intel_dp);
        }
 
-       if (drm_dp_dpcd_readb(&intel_dp->aux, DP_SINK_COUNT,
-                             &intel_dp->sink_count) <= 0)
+       if (drm_dp_dpcd_readb(&intel_dp->aux, DP_SINK_COUNT, &sink_count) <= 0)
                return false;
 
        /*
@@ -3746,7 +3747,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
         * a member variable in intel_dp will track any changes
         * between short pulse interrupts.
         */
-       intel_dp->sink_count = DP_GET_SINK_COUNT(intel_dp->sink_count);
+       intel_dp->sink_count = DP_GET_SINK_COUNT(sink_count);
 
        /*
         * SINK_COUNT == 0 and DOWNSTREAM_PORT_PRESENT == 1 implies that