mei: vsc: Unregister interrupt handler for system suspend

Unregister the MEI VSC interrupt handler before system suspend and
re-register it at system resume time. This mirrors implementation of other
MEI devices.

This patch fixes the bug that causes continuous stream of MEI VSC errors
after system resume.

Fixes: 386a766 ("mei: Add MEI hardware support for IVSC device")
Cc: stable@vger.kernel.org # for 6.8
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20240403051341.3534650-2-wentong.wu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/platform-vsc.c

@@ -400,25 +400,40 @@ static void mei_vsc_remove(struct platform_device *pdev)
 static int mei_vsc_suspend(struct device *dev)
 {
 	struct mei_device *mei_dev = dev_get_drvdata(dev);
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
 
 	mei_stop(mei_dev);
 
+	mei_disable_interrupts(mei_dev);
+
+	vsc_tp_free_irq(hw->tp);
+
 	return 0;
 }
 
 static int mei_vsc_resume(struct device *dev)
 {
 	struct mei_device *mei_dev = dev_get_drvdata(dev);
+	struct mei_vsc_hw *hw = mei_dev_to_vsc_hw(mei_dev);
 	int ret;
 
-	ret = mei_restart(mei_dev);
+	ret = vsc_tp_request_irq(hw->tp);
 	if (ret)
 		return ret;
 
+	ret = mei_restart(mei_dev);
+	if (ret)
+		goto err_free;
+
 	/* start timer if stopped in suspend */
 	schedule_delayed_work(&mei_dev->timer_work, HZ);
 
 	return 0;
+
+err_free:
+	vsc_tp_free_irq(hw->tp);
+
+	return ret;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(mei_vsc_pm_ops, mei_vsc_suspend, mei_vsc_resume);

drivers/misc/mei/vsc-tp.c

@@ -94,6 +94,27 @@ static const struct acpi_gpio_mapping vsc_tp_acpi_gpios[] = {
 	{}
 };
 
+static irqreturn_t vsc_tp_isr(int irq, void *data)
+{
+	struct vsc_tp *tp = data;
+
+	atomic_inc(&tp->assert_cnt);
+
+	wake_up(&tp->xfer_wait);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t vsc_tp_thread_isr(int irq, void *data)
+{
+	struct vsc_tp *tp = data;
+
+	if (tp->event_notify)
+		tp->event_notify(tp->event_notify_context);
+
+	return IRQ_HANDLED;
+}
+
 /* wakeup firmware and wait for response */
 static int vsc_tp_wakeup_request(struct vsc_tp *tp)
 {
@@ -383,6 +404,37 @@ int vsc_tp_register_event_cb(struct vsc_tp *tp, vsc_tp_event_cb_t event_cb,
 }
 EXPORT_SYMBOL_NS_GPL(vsc_tp_register_event_cb, VSC_TP);
 
+/**
+ * vsc_tp_request_irq - request irq for vsc_tp device
+ * @tp: vsc_tp device handle
+ */
+int vsc_tp_request_irq(struct vsc_tp *tp)
+{
+	struct spi_device *spi = tp->spi;
+	struct device *dev = &spi->dev;
+	int ret;
+
+	irq_set_status_flags(spi->irq, IRQ_DISABLE_UNLAZY);
+	ret = request_threaded_irq(spi->irq, vsc_tp_isr, vsc_tp_thread_isr,
+				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				   dev_name(dev), tp);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(vsc_tp_request_irq, VSC_TP);
+
+/**
+ * vsc_tp_free_irq - free irq for vsc_tp device
+ * @tp: vsc_tp device handle
+ */
+void vsc_tp_free_irq(struct vsc_tp *tp)
+{
+	free_irq(tp->spi->irq, tp);
+}
+EXPORT_SYMBOL_NS_GPL(vsc_tp_free_irq, VSC_TP);
+
 /**
  * vsc_tp_intr_synchronize - synchronize vsc_tp interrupt
  * @tp: vsc_tp device handle
@@ -413,27 +465,6 @@ void vsc_tp_intr_disable(struct vsc_tp *tp)
 }
 EXPORT_SYMBOL_NS_GPL(vsc_tp_intr_disable, VSC_TP);
 
-static irqreturn_t vsc_tp_isr(int irq, void *data)
-{
-	struct vsc_tp *tp = data;
-
-	atomic_inc(&tp->assert_cnt);
-
-	wake_up(&tp->xfer_wait);
-
-	return IRQ_WAKE_THREAD;
-}
-
-static irqreturn_t vsc_tp_thread_isr(int irq, void *data)
-{
-	struct vsc_tp *tp = data;
-
-	if (tp->event_notify)
-		tp->event_notify(tp->event_notify_context);
-
-	return IRQ_HANDLED;
-}
-
 static int vsc_tp_match_any(struct acpi_device *adev, void *data)
 {
 	struct acpi_device **__adev = data;
@@ -490,10 +521,9 @@ static int vsc_tp_probe(struct spi_device *spi)
 	tp->spi = spi;
 
 	irq_set_status_flags(spi->irq, IRQ_DISABLE_UNLAZY);
-	ret = devm_request_threaded_irq(dev, spi->irq, vsc_tp_isr,
-					vsc_tp_thread_isr,
-					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
-					dev_name(dev), tp);
+	ret = request_threaded_irq(spi->irq, vsc_tp_isr, vsc_tp_thread_isr,
+				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				   dev_name(dev), tp);
 	if (ret)
 		return ret;
 
@@ -522,6 +552,8 @@ static int vsc_tp_probe(struct spi_device *spi)
 err_destroy_lock:
 	mutex_destroy(&tp->mutex);
 
+	free_irq(spi->irq, tp);
+
 	return ret;
 }
 
@@ -532,6 +564,8 @@ static void vsc_tp_remove(struct spi_device *spi)
 	platform_device_unregister(tp->pdev);
 
 	mutex_destroy(&tp->mutex);
+
+	free_irq(spi->irq, tp);
 }
 
 static const struct acpi_device_id vsc_tp_acpi_ids[] = {

drivers/misc/mei/vsc-tp.h

@@ -37,6 +37,9 @@ int vsc_tp_xfer(struct vsc_tp *tp, u8 cmd, const void *obuf, size_t olen,
 int vsc_tp_register_event_cb(struct vsc_tp *tp, vsc_tp_event_cb_t event_cb,
 			     void *context);
 
+int vsc_tp_request_irq(struct vsc_tp *tp);
+void vsc_tp_free_irq(struct vsc_tp *tp);
+
 void vsc_tp_intr_enable(struct vsc_tp *tp);
 void vsc_tp_intr_disable(struct vsc_tp *tp);
 void vsc_tp_intr_synchronize(struct vsc_tp *tp);