diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 1474f84fdbd0..42bdca47c5d6 100644 --- 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 |