On Fri, Sep 18, 2020 at 07:02:27PM -0700, Bhaumik Bhatt wrote:
> MHI work is currently scheduled on the global/system workqueue and can
> encounter delays on a stressed system. To avoid those unforeseen
> delays which can hamper bootup or shutdown times, use a dedicated high
> priority workqueue instead of the global/system workqueue.
>
> Signed-off-by: Bhaumik Bhatt <bbh...@codeaurora.org>
> ---
> drivers/bus/mhi/core/init.c | 7 +++++++
> drivers/bus/mhi/core/pm.c | 2 +-
> include/linux/mhi.h | 2 ++
> 3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 1b4161e..ca32563 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -890,6 +890,11 @@ int mhi_register_controller(struct mhi_controller
> *mhi_cntrl,
> INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
> init_waitqueue_head(&mhi_cntrl->state_event);
>
> + mhi_cntrl->hiprio_wq = alloc_ordered_workqueue
> + ("mhi_hiprio_wq", WQ_MEM_RECLAIM | WQ_HIGHPRI);
> + if (!mhi_cntrl->hiprio_wq)
Printing an error here would be helpful.
> + goto error_alloc_cmd;
> +
> mhi_cmd = mhi_cntrl->mhi_cmd;
> for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
> spin_lock_init(&mhi_cmd->lock);
> @@ -977,10 +982,12 @@ int mhi_register_controller(struct mhi_controller
> *mhi_cntrl,
>
> error_alloc_dev:
> kfree(mhi_cntrl->mhi_cmd);
> + destroy_workqueue(mhi_cntrl->hiprio_wq);
So you're destroying the queue two times? You don't need it here.
>
> error_alloc_cmd:
> vfree(mhi_cntrl->mhi_chan);
> kfree(mhi_cntrl->mhi_event);
> + destroy_workqueue(mhi_cntrl->hiprio_wq);
>
> return ret;
> }
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index ce4d969..9d4789d 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -597,7 +597,7 @@ int mhi_queue_state_transition(struct mhi_controller
> *mhi_cntrl,
> list_add_tail(&item->node, &mhi_cntrl->transition_list);
> spin_unlock_irqrestore(&mhi_cntrl->transition_lock, flags);
>
> - schedule_work(&mhi_cntrl->st_worker);
> + queue_work(mhi_cntrl->hiprio_wq, &mhi_cntrl->st_worker);
>
> return 0;
> }
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index fb45a0f..7677676 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -338,6 +338,7 @@ struct mhi_controller_config {
> * @wlock: Lock for protecting device wakeup
> * @mhi_link_info: Device bandwidth info
> * @st_worker: State transition worker
> + * @hiprio_wq: High priority workqueue
For what? Please state the purpose.
Thanks,
Mani
> * @state_event: State change event
> * @status_cb: CB function to notify power states of the device (required)
> * @wake_get: CB function to assert device wake (optional)
> @@ -421,6 +422,7 @@ struct mhi_controller {
> spinlock_t wlock;
> struct mhi_link_info mhi_link_info;
> struct work_struct st_worker;
> + struct workqueue_struct *hiprio_wq;
> wait_queue_head_t state_event;
>
> void (*status_cb)(struct mhi_controller *mhi_cntrl,
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
