From 70101c3217aec849d509040554ef0cf7c0f1ef56 Mon Sep 17 00:00:00 2001 From: Kuan-Wei Chiu Date: Tue, 7 Apr 2026 09:49:00 +0000 Subject: [PATCH] virtio: mmio: Return error codes on probe failures Currently, virtio_mmio_probe() returns 0 when it encounters an invalid magic value, an unsupported version, or a dummy device (ID 0). In U-Boot's driver model, returning 0 indicates a successful probe. This causes the system to incorrectly register and activate invalid or placeholder devices, potentially leading to undefined behavior or crashes later on. Update the probe function to return appropriate error codes (-ENODEV for invalid magic values and dummy devices, and -ENXIO for unsupported versions). This fix correctly instructs the DM to abort the binding process. Fixes: fdc4aca89ecb ("virtio: Add virtio over mmio transport driver") Signed-off-by: Kuan-Wei Chiu Acked-by: Daniel Palmer --- drivers/virtio/virtio_mmio.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 1cd737aca24..62afe609ec0 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -354,7 +354,7 @@ static int virtio_mmio_probe(struct udevice *udev) magic = readl(priv->base + VIRTIO_MMIO_MAGIC_VALUE); if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) { debug("(%s): wrong magic value 0x%08x!\n", udev->name, magic); - return 0; + return -ENODEV; } /* Check device version */ @@ -362,7 +362,7 @@ static int virtio_mmio_probe(struct udevice *udev) if (priv->version < 1 || priv->version > 2) { debug("(%s): version %d not supported!\n", udev->name, priv->version); - return 0; + return -ENXIO; } /* Check device ID */ @@ -372,7 +372,7 @@ static int virtio_mmio_probe(struct udevice *udev) * virtio-mmio device with an ID 0 is a (dummy) placeholder * with no function. End probing now with no error reported. */ - return 0; + return -ENODEV; } uc_priv->vendor = readl(priv->base + VIRTIO_MMIO_VENDOR_ID);