Messages in this thread | | | Date | Mon, 24 May 2021 09:22:43 -0700 | From | khsieh@codeauro ... | Subject | Re: [PATCH 2/3] drm/msm/dp: Shrink locking area of dp_aux_transfer() |
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On 2021-05-07 14:25, Stephen Boyd wrote: > 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>
Reviewed-by: Kuogee Hsieh <khsieh@codeaurora.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);
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