drm/dp_helper: don't return EPROTO for defers (v2)

If we get a msg.reply of REPLY_DEFER, we also get an err of 0
so we fail reads with 0 < size and return -EPROTO instead of trying
again.

v2: same fix in i2c code.

Found writing MST support.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Dave Airlie 2014-04-04 11:34:37 +10:00
parent f4d1b02129
commit aa17edff0a

View File

@ -386,11 +386,11 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
return err;
}
if (err < size)
return -EPROTO;
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) {
case DP_AUX_NATIVE_REPLY_ACK:
if (err < size)
return -EPROTO;
return err;
case DP_AUX_NATIVE_REPLY_NACK:
@ -599,8 +599,6 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
return err;
}
if (err < msg->size)
return -EPROTO;
switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) {
case DP_AUX_NATIVE_REPLY_ACK:
@ -639,6 +637,8 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
* Both native ACK and I2C ACK replies received. We
* can assume the transfer was successful.
*/
if (err < msg->size)
return -EPROTO;
return 0;
case DP_AUX_I2C_REPLY_NACK: