[17/38] drm/radeon/kms: fix regression in DP aux defer handling

[Greg KH]

3.0-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Alex Deucher <alexander.deucher@xxxxxxx>

commit 109bc10d30f33e84f1d7289f0039e0c858ade82f upstream.

An incorrect ordering in the error checking code lead
to DP aux defer being skipped in the aux native write
path.  Move the bytes transferred check (ret == 0)
below the defer check.

Tracked down by: Brad Campbell <brad@xxxxxxxxxxxxxxx>

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=41121

Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Brad Campbell <brad@xxxxxxxxxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/gpu/drm/radeon/atombios_dp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -158,14 +158,14 @@ static int radeon_dp_aux_native_read(str
 	while (1) {
 		ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
 					    msg, msg_bytes, recv, recv_bytes, delay, &ack);
-		if (ret == 0)
-			return -EPROTO;
 		if (ret < 0)
 			return ret;
 		if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
 			return ret;
 		else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
 			udelay(400);
+		else if (ret == 0)
+			return -EPROTO;
 		else
 			return -EIO;
 	}


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/