drm/radeon/kms: retry aux transactions if there are status flags
commit 4f332844cc87c5f99c5300f788abbe8a8c731390 upstream.
If there are error flags in the aux status, retry the transaction.
This makes aux much more reliable, especially on llano systems.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 4da2388..79e8ebc 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -129,7 +129,9 @@
for (retry = 0; retry < 4; retry++) {
ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
msg, msg_bytes, NULL, 0, delay, &ack);
- if (ret < 0)
+ if (ret == -EBUSY)
+ continue;
+ else if (ret < 0)
return ret;
if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
return send_bytes;
@@ -160,7 +162,9 @@
for (retry = 0; retry < 4; retry++) {
ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
msg, msg_bytes, recv, recv_bytes, delay, &ack);
- if (ret < 0)
+ if (ret == -EBUSY)
+ continue;
+ else if (ret < 0)
return ret;
if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
return ret;
@@ -236,7 +240,9 @@
for (retry = 0; retry < 4; retry++) {
ret = radeon_process_aux_ch(auxch,
msg, msg_bytes, reply, reply_bytes, 0, &ack);
- if (ret < 0) {
+ if (ret == -EBUSY)
+ continue;
+ else if (ret < 0) {
DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
return ret;
}