virtio_reset_device() promises that vq callbacks are not in progress
once it returns, but vm_reset() only writes 0 to the status register.
A callback that has already entered vring_interrupt() keeps running
while the driver tears down the state it uses.
Wait for a status read to return 0, so the device has stopped raising
interrupts, then synchronize_irq() as vp_reset() does with
vp_synchronize_vectors().
Fixes: edfd52e63672 ("virtio: Add platform bus driver for memory mapped virtio
device")
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <[email protected]>
---
drivers/virtio/virtio_mmio.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 510b7c4efdff8..a2ca03dbe803d 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -55,6 +55,7 @@
#define pr_fmt(fmt) "virtio-mmio: " fmt
#include <linux/acpi.h>
+#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
@@ -254,6 +255,11 @@ static void vm_reset(struct virtio_device *vdev)
/* 0 status means a reset. */
writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
+
+ /* Wait for reset completion before flushing callbacks. */
+ while (vm_get_status(vdev))
+ fsleep(1000);
+ synchronize_irq(platform_get_irq(vm_dev->pdev, 0));
}
--
2.53.0
