From 47327fdd7e85ed4a90b76c2fcf69967f98230935 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Fri, 7 May 2021 14:25:04 -0700 Subject: drm/msm/dp: Shrink locking area of dp_aux_transfer() 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 Cc: Abhinav Kumar Cc: Kuogee Hsieh Cc: aravindh@codeaurora.org Cc: Sean Paul Signed-off-by: Stephen Boyd Reviewed-by: Kuogee Hsieh Link: https://lore.kernel.org/r/20210507212505.1224111-3-swboyd@chromium.org Signed-off-by: Rob Clark --- 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); -- cgit