[PATCH] drm/dp_helper: don't return EPROTO for defers (v2)
Timo Aaltonen
tjaalton at ubuntu.com
Thu Apr 30 06:32:40 UTC 2015
From: Dave Airlie <airlied at 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 at intel.com>
Reviewed-by: Thierry Reding <treding at nvidia.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>
(cherry picked from commit aa17edff0afa893b5ab1dd60d842cc6f42e847b4)
Signed-off-by: Timo Aaltonen <timo.aaltonen at 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:
--
2.1.4
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