diff options
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 4 | ||||
| -rw-r--r-- | include/drm/drm_dp_helper.h | 4 |
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index bcfb0d07718e..4b6e6f3ba0a1 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -577,7 +577,9 @@ static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) /* * Transfer a single I2C-over-AUX message and handle various error conditions, - * retrying the transaction as appropriate. + * retrying the transaction as appropriate. It is assumed that the + * aux->transfer function does not modify anything in the msg other than the + * reply field. */ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) { diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index b4f58914bf7d..cfcacec5b89d 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -456,6 +456,10 @@ struct drm_dp_aux_msg { * transactions. The drm_dp_aux_register_i2c_bus() function registers an * I2C adapter that can be passed to drm_probe_ddc(). Upon removal, drivers * should call drm_dp_aux_unregister_i2c_bus() to remove the I2C adapter. + * + * Note that the aux helper code assumes that the .transfer() function + * only modifies the reply field of the drm_dp_aux_msg structure. The + * retry logic and i2c helpers assume this is the case. */ struct drm_dp_aux { const char *name; |