diff options
| -rw-r--r-- | drivers/gpu/drm/display/drm_dp_helper.c | 39 | ||||
| -rw-r--r-- | include/drm/display/drm_dp_helper.h | 5 |
2 files changed, 28 insertions, 16 deletions
diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index 56c7e3318f01..f2a6559a2710 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -2137,14 +2137,17 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, for (i = 0; i < num; i++) { msg.address = msgs[i].addr; - drm_dp_i2c_msg_set_request(&msg, &msgs[i]); - /* Send a bare address packet to start the transaction. - * Zero sized messages specify an address only (bare - * address) transaction. - */ - msg.buffer = NULL; - msg.size = 0; - err = drm_dp_i2c_do_msg(aux, &msg); + + if (!aux->no_zero_sized) { + drm_dp_i2c_msg_set_request(&msg, &msgs[i]); + /* Send a bare address packet to start the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.buffer = NULL; + msg.size = 0; + err = drm_dp_i2c_do_msg(aux, &msg); + } /* * Reset msg.request in case in case it got @@ -2163,6 +2166,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, msg.buffer = msgs[i].buf + j; msg.size = min(transfer_size, msgs[i].len - j); + if (j + msg.size == msgs[i].len && aux->no_zero_sized) + msg.request &= ~DP_AUX_I2C_MOT; err = drm_dp_i2c_drain_msg(aux, &msg); /* @@ -2180,15 +2185,17 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, } if (err >= 0) err = num; - /* Send a bare address packet to close out the transaction. - * Zero sized messages specify an address only (bare - * address) transaction. - */ - msg.request &= ~DP_AUX_I2C_MOT; - msg.buffer = NULL; - msg.size = 0; - (void)drm_dp_i2c_do_msg(aux, &msg); + if (!aux->no_zero_sized) { + /* Send a bare address packet to close out the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.request &= ~DP_AUX_I2C_MOT; + msg.buffer = NULL; + msg.size = 0; + (void)drm_dp_i2c_do_msg(aux, &msg); + } return err; } diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index 7b19192c7031..e4ca35143ff9 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -518,6 +518,11 @@ struct drm_dp_aux { * @powered_down: If true then the remote endpoint is powered down. */ bool powered_down; + + /** + * @no_zero_sized: If the hw can't use zero sized transfers (NVIDIA) + */ + bool no_zero_sized; }; int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset); |