bus: mhi: core: Handle firmware load using state worker

Upon power up, driver queues firmware worker thread if the execution
environment is PBL. Firmware worker is blocked with a timeout until
state worker gets a chance to run and unblock firmware worker. An
endpoint power up failure can be seen if state worker gets a chance to
run after firmware worker has timed out. Remove this dependency and
handle firmware load directly using state worker thread.
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200521170249.21795-6-manivannan.sadhasivam@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/core/boot.c

@@ -377,30 +377,18 @@ static void mhi_firmware_copy(struct mhi_controller *mhi_cntrl,
 	}
 }
 
-void mhi_fw_load_worker(struct work_struct *work)
+void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 {
-	struct mhi_controller *mhi_cntrl;
 	const struct firmware *firmware = NULL;
 	struct image_info *image_info;
-	struct device *dev;
+	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	const char *fw_name;
 	void *buf;
 	dma_addr_t dma_addr;
 	size_t size;
 	int ret;
 
-	mhi_cntrl = container_of(work, struct mhi_controller, fw_worker);
-	dev = &mhi_cntrl->mhi_dev->dev;
-
-	dev_dbg(dev, "Waiting for device to enter PBL from: %s\n",
-		TO_MHI_EXEC_STR(mhi_cntrl->ee));
-
-	ret = wait_event_timeout(mhi_cntrl->state_event,
-				 MHI_IN_PBL(mhi_cntrl->ee) ||
-				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
-				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
-
-	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
 		dev_err(dev, "Device MHI is not in valid state\n");
 		return;
 	}

drivers/bus/mhi/core/init.c

@@ -835,7 +835,6 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	spin_lock_init(&mhi_cntrl->wlock);
 	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
 	INIT_WORK(&mhi_cntrl->syserr_worker, mhi_pm_sys_err_worker);
-	INIT_WORK(&mhi_cntrl->fw_worker, mhi_fw_load_worker);
 	init_waitqueue_head(&mhi_cntrl->state_event);
 
 	mhi_cmd = mhi_cntrl->mhi_cmd;

drivers/bus/mhi/core/internal.h

@@ -627,6 +627,7 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl);
 void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl);
 void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
 		      struct image_info *img_info);
+void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl);
 int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
 			struct mhi_chan *mhi_chan);
 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,

drivers/bus/mhi/core/pm.c

@@ -528,7 +528,6 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
 	dev_dbg(dev, "Waiting for all pending threads to complete\n");
 	wake_up_all(&mhi_cntrl->state_event);
 	flush_work(&mhi_cntrl->st_worker);
-	flush_work(&mhi_cntrl->fw_worker);
 
 	dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
 	device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device);
@@ -643,7 +642,7 @@ void mhi_pm_st_worker(struct work_struct *work)
 				mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
 			write_unlock_irq(&mhi_cntrl->pm_lock);
 			if (MHI_IN_PBL(mhi_cntrl->ee))
-				wake_up_all(&mhi_cntrl->state_event);
+				mhi_fw_load_handler(mhi_cntrl);
 			break;
 		case DEV_ST_TRANSITION_SBL:
 			write_lock_irq(&mhi_cntrl->pm_lock);
@@ -976,9 +975,6 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	next_state = MHI_IN_PBL(current_ee) ?
 		DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY;
 
-	if (next_state == DEV_ST_TRANSITION_PBL)
-		schedule_work(&mhi_cntrl->fw_worker);
-
 	mhi_queue_state_transition(mhi_cntrl, next_state);
 
 	mutex_unlock(&mhi_cntrl->pm_mutex);

include/linux/mhi.h

@@ -331,7 +331,6 @@ struct mhi_controller_config {
  * @wlock: Lock for protecting device wakeup
  * @mhi_link_info: Device bandwidth info
  * @st_worker: State transition worker
- * @fw_worker: Firmware download worker
  * @syserr_worker: System error worker
  * @state_event: State change event
  * @status_cb: CB function to notify power states of the device (required)
@@ -412,7 +411,6 @@ struct mhi_controller {
 	spinlock_t wlock;
 	struct mhi_link_info mhi_link_info;
 	struct work_struct st_worker;
-	struct work_struct fw_worker;
 	struct work_struct syserr_worker;
 	wait_queue_head_t state_event;