[PATCH 18/21] soundwire: amd: Synchronise parent IRQ and disable work on manager removal

[Lee Jones]

In the ACP top-half interrupt handlers, amd_manager is retrieved via
dev_get_drvdata() and used to schedule amd_sdw_irq_thread when
non-NULL.  If an interrupt is already in flight on another CPU when
amd_sdw_manager_remove() runs, the handler can call
schedule_work(&amd_manager->amd_sdw_irq_thread) after cancel_work_sync()
returns and after devm frees amd_manager.

Disable SoundWire interrupts, synchronise with the parent PCI device
IRQ, disable both manager work items with disable_work_sync(), and mask
interrupts again in case amd_sdw_update_slave_status_work() was running.

Fixes: f93b697ed98e ("soundwire: amd: cancel pending slave status handling workqueue during remove sequence")
Closes: https://sashiko.dev/#/bug/linux-ab458b2e-f505-4a41-8238-a93ceb5d9c77
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---
 drivers/soundwire/amd_manager.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index 1d8a08bda261..f39f4f04db7e 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -8,10 +8,12 @@
 #include <linux/completion.h>
 #include <linux/cleanup.h>
 #include <linux/device.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/pci.h>
 #include <linux/slab.h>
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_registers.h>
@@ -1199,8 +1201,11 @@ static void amd_sdw_manager_remove(struct platform_device *pdev)
 	pm_runtime_get_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
-	cancel_work_sync(&amd_manager->amd_sdw_irq_thread);
-	cancel_work_sync(&amd_manager->amd_sdw_work);
+	amd_disable_sdw_interrupts(amd_manager);
+	if (pdev->dev.parent && dev_is_pci(pdev->dev.parent))
+		synchronize_irq(to_pci_dev(pdev->dev.parent)->irq);
+	disable_work_sync(&amd_manager->amd_sdw_irq_thread);
+	disable_work_sync(&amd_manager->amd_sdw_work);
 	amd_disable_sdw_interrupts(amd_manager);
 	sdw_bus_master_delete(&amd_manager->bus);
 	ret = amd_disable_sdw_manager(amd_manager);
-- 
2.56.0.317.g454f8302e1-goog