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 <[email protected]>
---
drivers/bus/mhi/core/init.c | 8 ++++++++
drivers/bus/mhi/core/pm.c | 2 +-
include/linux/mhi.h | 2 ++
3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 0ffdebd..23b6dd6 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -880,6 +880,13 @@ 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) {
+ dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
+ 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);
@@ -969,6 +976,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
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 3de7b16..805b6fa74 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 d4841e5..8961cbc 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -337,6 +337,7 @@ 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 MHI work such as state transitions
* @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)
@@ -419,6 +420,7 @@ 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
On Thu, Oct 29, 2020 at 09:10:47PM -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 <[email protected]>
You are not destroying the workqueue in mhi_unregister_controller().
With that fixed,
Reviewed-by: Manivannan Sadhasivam <[email protected]>
Thanks,
Mani
> ---
> drivers/bus/mhi/core/init.c | 8 ++++++++
> drivers/bus/mhi/core/pm.c | 2 +-
> include/linux/mhi.h | 2 ++
> 3 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 0ffdebd..23b6dd6 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -880,6 +880,13 @@ 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) {
> + dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
> + 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);
> @@ -969,6 +976,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> 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 3de7b16..805b6fa74 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 d4841e5..8961cbc 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -337,6 +337,7 @@ 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 MHI work such as state transitions
> * @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)
> @@ -419,6 +420,7 @@ 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
>