[PATCH char-misc-next] mei: csc: add reset_prepare() and reset_done()

[Alexander Usyskin <alexander.usyskin@intel.com>]

Process PCI reset by stopping the flow in reset_prepare() and resuming
it in reset_done().
Consolidate start/stop flow in helper functions and stop polling thread
on suspend/resume by the way.

Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
 drivers/misc/mei/pci-csc.c | 77 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 54 insertions(+), 23 deletions(-)

diff --git a/drivers/misc/mei/pci-csc.c b/drivers/misc/mei/pci-csc.c
index fc09cfb5cdc7..7fbe4c1826bc 100644
--- a/drivers/misc/mei/pci-csc.c
+++ b/drivers/misc/mei/pci-csc.c
@@ -186,38 +186,63 @@ static void mei_csc_remove(struct pci_dev *pdev)
 	mei_deregister(mdev);
 }
 
-static int mei_csc_pci_prepare(struct device *dev)
+static void mei_csc_stop(struct mei_device *mdev)
 {
-	pm_runtime_resume(dev);
-	return 0;
-}
+	struct mei_me_hw *hw = to_me_hw(mdev);
 
-static int mei_csc_pci_suspend(struct device *dev)
-{
-	struct mei_device *mdev = dev_get_drvdata(dev);
+	scoped_guard(mutex, &mdev->device_lock) {
+		if (mei_me_hw_use_polling(hw))
+			hw->is_active = false;
+	}
 
 	mei_stop(mdev);
 
 	mei_disable_interrupts(mdev);
-
-	return 0;
 }
 
-static int mei_csc_pci_resume(struct device *dev)
+static int mei_csc_restart(struct mei_device *mdev)
 {
-	struct mei_device *mdev = dev_get_drvdata(dev);
+	struct mei_me_hw *hw = to_me_hw(mdev);
 	int err;
 
+	scoped_guard(mutex, &mdev->device_lock) {
+		if (mei_me_hw_use_polling(hw)) {
+			hw->is_active = true;
+			wake_up_interruptible(&hw->wait_active);
+		}
+	}
+
 	err = mei_restart(mdev);
 	if (err)
 		return err;
 
-	/* Start timer if stopped in suspend */
+	/* Start timer if stopped in stop */
 	schedule_delayed_work(&mdev->timer_work, HZ);
+	return 0;
+}
 
+static int mei_csc_pci_prepare(struct device *dev)
+{
+	pm_runtime_resume(dev);
 	return 0;
 }
 
+static int mei_csc_pci_suspend(struct device *dev)
+{
+	struct mei_device *mdev = dev_get_drvdata(dev);
+
+	mei_csc_stop(mdev);
+
+	return 0;
+}
+
+static int mei_csc_pci_resume(struct device *dev)
+{
+	struct mei_device *mdev = dev_get_drvdata(dev);
+
+	return mei_csc_restart(mdev);
+}
+
 static void mei_csc_pci_complete(struct device *dev)
 {
 	pm_runtime_suspend(dev);
@@ -316,28 +341,34 @@ static pci_ers_result_t mei_csc_pci_error_slot_reset(struct pci_dev *pdev)
 static void mei_csc_pci_error_resume(struct pci_dev *pdev)
 {
 	struct mei_device *mdev = pci_get_drvdata(pdev);
-	struct mei_me_hw *hw = to_me_hw(mdev);
 
 	dev_info(&pdev->dev, "error recovery: resume\n");
 
-	scoped_guard(mutex, &mdev->device_lock) {
-		if (mei_me_hw_use_polling(hw)) {
-			hw->is_active = true;
-			wake_up_interruptible(&hw->wait_active);
-		}
-	}
+	mei_csc_restart(mdev);
+}
 
-	if (mei_restart(mdev))
-		return;
+static void mei_csc_reset_prepare(struct pci_dev *pdev)
+{
+	struct mei_device *mdev = pci_get_drvdata(pdev);
 
-	/* Start timer if stopped in error */
-	schedule_delayed_work(&mdev->timer_work, HZ);
+	mei_csc_stop(mdev);
+}
+
+static void mei_csc_reset_done(struct pci_dev *pdev)
+{
+	struct mei_device *mdev = pci_get_drvdata(pdev);
+
+	pci_set_master(pdev);
+
+	mei_csc_restart(mdev);
 }
 
 static const struct pci_error_handlers mei_csc_pci_error_handlers = {
 	.error_detected = mei_csc_pci_error_detected,
 	.slot_reset     = mei_csc_pci_error_slot_reset,
 	.resume         = mei_csc_pci_error_resume,
+	.reset_prepare  = mei_csc_reset_prepare,
+	.reset_done     = mei_csc_reset_done,
 };
 
 static const struct dev_pm_ops mei_csc_pm_ops = {

---
base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
change-id: 20261112-csc_reset_prepare_done-b9310b3fa62c

Best regards,
-- 
Alexander Usyskin <alexander.usyskin@intel.com>