| Message ID | 1430375560-14507-2-git-send-email-tjaalton@ubuntu.com |
|---|---|
| State | New |
| Headers | show |
Clean cherry-pick, fixes a serious bug. --chris On 04/30/2015 01:32 AM, Timo Aaltonen wrote: > From: Dave Airlie <airlied@redhat.com> > > BugLink: http://bugs.launchpad.net/bugs/1450322 > > 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> > (cherry picked from commit aa17edff0afa893b5ab1dd60d842cc6f42e847b4) > Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index f4babed..2767148 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -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: >
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index f4babed..2767148 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -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: