We don't need to hold the lock to inspect the message we're going to transfer, and we don't need to clear the busy flag either. Take the lock later and bail out earlier if conditions aren't met.
Cc: Dmitry Baryshkov dmitry.baryshkov@linaro.org Cc: Abhinav Kumar abhinavk@codeaurora.org Cc: Kuogee Hsieh khsieh@codeaurora.org Cc: aravindh@codeaurora.org Cc: Sean Paul sean@poorly.run Signed-off-by: Stephen Boyd swboyd@chromium.org --- drivers/gpu/drm/msm/dp/dp_aux.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c index 91188466cece..b49810396513 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.c +++ b/drivers/gpu/drm/msm/dp/dp_aux.c @@ -329,30 +329,29 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux, ssize_t ret; int const aux_cmd_native_max = 16; int const aux_cmd_i2c_max = 128; - struct dp_aux_private *aux = container_of(dp_aux, - struct dp_aux_private, dp_aux); + struct dp_aux_private *aux;
- mutex_lock(&aux->mutex); + aux = container_of(dp_aux, struct dp_aux_private, dp_aux);
aux->native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
/* Ignore address only message */ - if ((msg->size == 0) || (msg->buffer == NULL)) { + if (msg->size == 0 || !msg->buffer) { msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; - ret = msg->size; - goto unlock_exit; + return msg->size; }
/* msg sanity check */ - if ((aux->native && (msg->size > aux_cmd_native_max)) || - (msg->size > aux_cmd_i2c_max)) { + if ((aux->native && msg->size > aux_cmd_native_max) || + msg->size > aux_cmd_i2c_max) { DRM_ERROR("%s: invalid msg: size(%zu), request(%x)\n", __func__, msg->size, msg->request); - ret = -EINVAL; - goto unlock_exit; + return -EINVAL; }
+ mutex_lock(&aux->mutex); + dp_aux_update_offset_and_segment(aux, msg); dp_aux_transfer_helper(aux, msg, true);