drm/i915: Warn about aux msg buffer vs. size mismatch

If we have have a buffer, we should also have a size, and vice versa.
Let's check it both ways instead of just one.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469717704-13020-1-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 21b04c3..001f74f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1041,10 +1041,10 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
                if (WARN_ON(txsize > 20))
                        return -E2BIG;
 
+               WARN_ON(!msg->buffer != !msg->size);
+
                if (msg->buffer)
                        memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);
-               else
-                       WARN_ON(msg->size);
 
                ret = intel_dp_aux_ch(intel_dp, txbuf, txsize, rxbuf, rxsize);
                if (ret > 0) {