drm/i915/lspcon: Fail LSPCON probe if the start of DPCD can't be read
All types of DP devices (eDP, DP sink, DP branch) will fail their probe
if the start of DPCD can't be read. The LSPCON PCON functionality also
depends on accessing this area, so fail the probe if the read fails.
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477326811-30431-6-git-send-email-imre.deak@intel.com
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index bff27b7..07a502f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3497,7 +3497,7 @@ intel_dp_link_down(struct intel_dp *intel_dp)
intel_dp->DP = DP;
}
-static bool
+bool
intel_dp_read_dpcd(struct intel_dp *intel_dp)
{
if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 65ebe92..b958326 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1467,6 +1467,8 @@ static inline unsigned int intel_dp_unused_lane_mask(int lane_count)
return ~((1 << lane_count) - 1) & 0xf;
}
+bool intel_dp_read_dpcd(struct intel_dp *intel_dp);
+
/* intel_dp_aux_backlight.c */
int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector);
diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
index 632149c..23b817a 100644
--- a/drivers/gpu/drm/i915/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -131,6 +131,11 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
}
}
+ if (!intel_dp_read_dpcd(dp)) {
+ DRM_ERROR("LSPCON DPCD read failed\n");
+ return false;
+ }
+
DRM_DEBUG_KMS("Success: LSPCON init\n");
return true;
}