drm/radeon: retry dcpd fetch

Retry the dpcd fetch several times.  Some eDP panels
fail several times before the fetch is successful.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=73530

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Alex Deucher 2015-05-18 10:38:25 -04:00
parent 755c814a7d
commit 0f28d1281b
1 changed files with 11 additions and 9 deletions

View File

@ -421,19 +421,21 @@ bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
{
struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
u8 msg[DP_DPCD_SIZE];
int ret;
int ret, i;
ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_DPCD_REV, msg,
DP_DPCD_SIZE);
if (ret > 0) {
memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
for (i = 0; i < 7; i++) {
ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, DP_DPCD_REV, msg,
DP_DPCD_SIZE);
if (ret == DP_DPCD_SIZE) {
memcpy(dig_connector->dpcd, msg, DP_DPCD_SIZE);
DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
dig_connector->dpcd);
DRM_DEBUG_KMS("DPCD: %*ph\n", (int)sizeof(dig_connector->dpcd),
dig_connector->dpcd);
radeon_dp_probe_oui(radeon_connector);
radeon_dp_probe_oui(radeon_connector);
return true;
return true;
}
}
dig_connector->dpcd[0] = 0;
return false;