[PATCH v4 3/3] HID: Intel-thc-hid: Intel-quickspi: Refine recover callback

[Even Xu <even.xu@intel.com>]

Refine recover flow:
1. Use workqueue to handle recover flow instead of processing in irq
   handler.
2. Call thc_rxdma_reset() API to simplify the recover operation.
3. Disable interrupt during whole recover flow.
4. If recover fails, disable interrupt to avoid interrupt storm.

Signed-off-by: Even Xu <even.xu@intel.com>
---
 .../intel-quickspi/pci-quickspi.c             | 71 +++++++++++--------
 .../intel-quickspi/quickspi-dev.h             |  6 ++
 2 files changed, 49 insertions(+), 28 deletions(-)

diff --git a/drivers/hid/intel-thc-hid/intel-quickspi/pci-quickspi.c b/drivers/hid/intel-thc-hid/intel-quickspi/pci-quickspi.c
index f669235f1883..f048f5b1f7eb 100644
--- a/drivers/hid/intel-thc-hid/intel-quickspi/pci-quickspi.c
+++ b/drivers/hid/intel-thc-hid/intel-quickspi/pci-quickspi.c
@@ -252,34 +252,31 @@ static irqreturn_t quickspi_irq_quick_handler(int irq, void *dev_id)
 }
 
 /**
- * try_recover - Try to recovery THC and Device
- * @qsdev: pointer to quickspi device
+ * try_recover - Recover callback to recover THC
+ * @work: pointer to work_struct
  *
- * This function is a error handler, called when fatal error happens.
- * It try to reset Touch Device and re-configure THC to recovery
+ * This function is an error handler, called when fatal error happens.
+ * It try to reset Touch Device and re-configure THC to recover
  * transferring between Device and THC.
- *
- * Return: 0 if successful or error code on failed.
  */
-static int try_recover(struct quickspi_device *qsdev)
+static void try_recover(struct work_struct *work)
 {
-	int ret;
+	struct quickspi_device *qsdev = container_of(work, struct quickspi_device, recover_work);
 
-	ret = reset_tic(qsdev);
-	if (ret) {
-		dev_err(qsdev->dev, "Reset touch device failed, ret = %d\n", ret);
-		return ret;
-	}
+	if (READ_ONCE(qsdev->recovery_disabled))
+		return;
 
-	thc_dma_unconfigure(qsdev->thc_hw);
+	if (pm_runtime_resume_and_get(qsdev->dev))
+		return;
 
-	ret = thc_dma_configure(qsdev->thc_hw);
-	if (ret) {
-		dev_err(qsdev->dev, "Re-configure THC DMA failed, ret = %d\n", ret);
-		return ret;
-	}
+	thc_interrupt_enable(qsdev->thc_hw, false);
 
-	return 0;
+	if (thc_rxdma_reset(qsdev->thc_hw))
+		qsdev->state = QUICKSPI_DISABLED;
+	else
+		thc_interrupt_enable(qsdev->thc_hw, true);
+
+	pm_runtime_put_autosuspend(qsdev->dev);
 }
 
 /**
@@ -337,11 +334,10 @@ static irqreturn_t quickspi_irq_thread_handler(int irq, void *dev_id)
 	}
 
 end:
-	thc_interrupt_enable(qsdev->thc_hw, true);
-
 	if (err_recover)
-		if (try_recover(qsdev))
-			qsdev->state = QUICKSPI_DISABLED;
+		schedule_work(&qsdev->recover_work);
+	else
+		thc_interrupt_enable(qsdev->thc_hw, true);
 
 	pm_runtime_put_autosuspend(qsdev->dev);
 
@@ -385,6 +381,8 @@ static struct quickspi_device *quickspi_dev_init(struct pci_dev *pdev, void __io
 	init_waitqueue_head(&qsdev->report_desc_got_wq);
 	init_waitqueue_head(&qsdev->get_report_cmpl_wq);
 	init_waitqueue_head(&qsdev->set_report_cmpl_wq);
+	WRITE_ONCE(qsdev->recovery_disabled, false);
+	INIT_WORK(&qsdev->recover_work, try_recover);
 
 	/* thc hw init */
 	qsdev->thc_hw = thc_dev_init(qsdev->dev, qsdev->mem_addr);
@@ -461,6 +459,10 @@ static struct quickspi_device *quickspi_dev_init(struct pci_dev *pdev, void __io
  */
 static void quickspi_dev_deinit(struct quickspi_device *qsdev)
 {
+	WRITE_ONCE(qsdev->recovery_disabled, true);
+	cancel_work_sync(&qsdev->recover_work);
+
+	thc_interrupt_quiesce(qsdev->thc_hw, true);
 	thc_interrupt_enable(qsdev->thc_hw, false);
 	thc_ltr_unconfig(qsdev->thc_hw);
 	thc_wot_unconfig(qsdev->thc_hw);
@@ -711,12 +713,13 @@ static void quickspi_remove(struct pci_dev *pdev)
 		return;
 
 	quickspi_hid_remove(qsdev);
+
+	quickspi_dev_deinit(qsdev);
+
 	quickspi_dma_deinit(qsdev);
 
 	pm_runtime_get_noresume(qsdev->dev);
 
-	quickspi_dev_deinit(qsdev);
-
 	pci_clear_master(pdev);
 }
 
@@ -737,10 +740,10 @@ static void quickspi_shutdown(struct pci_dev *pdev)
 	if (!qsdev)
 		return;
 
+	quickspi_dev_deinit(qsdev);
+
 	/* Must stop DMA before reboot to avoid DMA entering into unknown state */
 	quickspi_dma_deinit(qsdev);
-
-	quickspi_dev_deinit(qsdev);
 }
 
 static int quickspi_suspend(struct device *device)
@@ -759,6 +762,9 @@ static int quickspi_suspend(struct device *device)
 			return ret;
 	}
 
+	WRITE_ONCE(qsdev->recovery_disabled, true);
+	cancel_work_sync(&qsdev->recover_work);
+
 	ret = thc_interrupt_quiesce(qsdev->thc_hw, true);
 	if (ret)
 		return ret;
@@ -796,6 +802,8 @@ static int quickspi_resume(struct device *device)
 	if (ret)
 		return ret;
 
+	WRITE_ONCE(qsdev->recovery_disabled, false);
+
 	if (!device_may_wakeup(qsdev->dev))
 		return quickspi_set_power(qsdev, HIDSPI_ON);
 
@@ -812,6 +820,9 @@ static int quickspi_freeze(struct device *device)
 	if (!qsdev)
 		return -ENODEV;
 
+	WRITE_ONCE(qsdev->recovery_disabled, true);
+	cancel_work_sync(&qsdev->recover_work);
+
 	ret = thc_interrupt_quiesce(qsdev->thc_hw, true);
 	if (ret)
 		return ret;
@@ -843,6 +854,8 @@ static int quickspi_thaw(struct device *device)
 	if (ret)
 		return ret;
 
+	WRITE_ONCE(qsdev->recovery_disabled, false);
+
 	return 0;
 }
 
@@ -867,6 +880,8 @@ static int quickspi_poweroff(struct device *device)
 
 	thc_ltr_unconfig(qsdev->thc_hw);
 
+	quickspi_dev_deinit(qsdev);
+
 	quickspi_dma_deinit(qsdev);
 
 	return 0;
diff --git a/drivers/hid/intel-thc-hid/intel-quickspi/quickspi-dev.h b/drivers/hid/intel-thc-hid/intel-quickspi/quickspi-dev.h
index bf5e18f5a5f4..2936c8b1532c 100644
--- a/drivers/hid/intel-thc-hid/intel-quickspi/quickspi-dev.h
+++ b/drivers/hid/intel-thc-hid/intel-quickspi/quickspi-dev.h
@@ -8,6 +8,7 @@
 #include <linux/hid-over-spi.h>
 #include <linux/sizes.h>
 #include <linux/wait.h>
+#include <linux/workqueue.h>
 
 #include "quickspi-protocol.h"
 
@@ -126,6 +127,8 @@ struct acpi_device;
  * @get_feature_cmpl: indicate get feature received or not
  * @set_feature_cmpl_wq: workqueue for waiting set feature to device
  * @set_feature_cmpl: indicate set feature send complete or not
+ * @recover_work: Work structure for recovery
+ * @recovery_disabled: Whether recovery work is blocked during teardown
  */
 struct quickspi_device {
 	struct device *dev;
@@ -173,6 +176,9 @@ struct quickspi_device {
 
 	wait_queue_head_t set_report_cmpl_wq;
 	bool set_report_cmpl;
+
+	struct work_struct recover_work;
+	bool recovery_disabled;
 };
 
 #endif /* _QUICKSPI_DEV_H_ */
-- 
2.43.0