drm/radeon/kms: fix regression in DP aux defer handling
Alex Deucher [Mon, 3 Oct 2011 13:13:45 +0000 (09:13 -0400)]
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@fnarfbargle.com>

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

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Brad Campbell <brad@fnarfbargle.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/atombios_dp.c

index 7ad43c6..f526fa7 100644 (file)
@@ -158,14 +158,14 @@ static int radeon_dp_aux_native_read(struct radeon_connector *radeon_connector,
        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;
        }