The URB buffer allocation of pwc driver involves with the dma_map_single(), and it needs to pass the right device. Currently it passes usb_device.dev, but it's no real device that manages the DMA. Since the passed device has no DMA mask set up, now the pwc driver hits the WARN_ON_ONCE() check in dma_map_page_attrs() (that was introduced in 5.10), resulting in an error at URB allocations. Eventually this ended up with the black output. This patch fixes the bug by passing the proper device, the bus controller, to make the URB allocation and map working again. BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1181133 Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> --- drivers/media/usb/pwc/pwc-if.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c index 61869636ec61..d771160bb168 100644 --- a/drivers/media/usb/pwc/pwc-if.c +++ b/drivers/media/usb/pwc/pwc-if.c @@ -461,7 +461,7 @@ static int pwc_isoc_init(struct pwc_device *pdev) urb->pipe = usb_rcvisocpipe(udev, pdev->vendpoint); urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; urb->transfer_buffer_length = ISO_BUFFER_SIZE; - urb->transfer_buffer = pwc_alloc_urb_buffer(&udev->dev, + urb->transfer_buffer = pwc_alloc_urb_buffer(udev->bus->controller, urb->transfer_buffer_length, &urb->transfer_dma); if (urb->transfer_buffer == NULL) { @@ -524,7 +524,7 @@ static void pwc_iso_free(struct pwc_device *pdev) if (urb) { PWC_DEBUG_MEMORY("Freeing URB\n"); if (urb->transfer_buffer) - pwc_free_urb_buffer(&urb->dev->dev, + pwc_free_urb_buffer(urb->dev->bus->controller, urb->transfer_buffer_length, urb->transfer_buffer, urb->transfer_dma); -- 2.26.2
