drm/i915/dp: Fetch downstream port info if needed during DPCD fetch

v2: Fix parenthesis mismatch, spotted by Jani Nikula

Tested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
[danvet: Fixup merge conflict and MAX_DOWNSTREAM #define as spotted by
Jani.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1474f84..42bdca4 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -37,6 +37,7 @@
 #include "i915_drm.h"
 #include "i915_drv.h"
 
+#define DP_RECEIVER_CAP_SIZE   0xf
 #define DP_LINK_STATUS_SIZE    6
 #define DP_LINK_CHECK_TIMEOUT  (10 * 1000)
 
@@ -1964,12 +1965,25 @@ static bool
 intel_dp_get_dpcd(struct intel_dp *intel_dp)
 {
        if (intel_dp_aux_native_read_retry(intel_dp, 0x000, intel_dp->dpcd,
-                                          sizeof(intel_dp->dpcd)) &&
-           (intel_dp->dpcd[DP_DPCD_REV] != 0)) {
-               return true;
-       }
+                                          sizeof(intel_dp->dpcd)) == 0)
+               return false; /* aux transfer failed */
 
-       return false;
+       if (intel_dp->dpcd[DP_DPCD_REV] == 0)
+               return false; /* DPCD not present */
+
+       if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+             DP_DWN_STRM_PORT_PRESENT))
+               return true; /* native DP sink */
+
+       if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
+               return true; /* no per-port downstream info */
+
+       if (intel_dp_aux_native_read_retry(intel_dp, DP_DOWNSTREAM_PORT_0,
+                                          intel_dp->downstream_ports,
+                                          DP_MAX_DOWNSTREAM_PORTS) == 0)
+               return false; /* downstream port status fetch failed */
+
+       return true;
 }
 
 static void

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 351fd71..79f8ed6 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -332,6 +332,7 @@ struct intel_hdmi {
 };
 
 #define DP_RECEIVER_CAP_SIZE           0xf
+#define DP_MAX_DOWNSTREAM_PORTS                0x10
 #define DP_LINK_CONFIGURATION_SIZE     9
 
 struct intel_dp {
@@ -346,6 +347,7 @@ struct intel_dp {
        uint8_t link_bw;
        uint8_t lane_count;
        uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
+       uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
        struct i2c_adapter adapter;
        struct i2c_algo_dp_aux_data algo;
        bool is_pch_edp;