Re: [PATCH] USB: usbfs: fix mmap dma mismatch

[Christoph Hellwig]

On Thu, May 14, 2020 at 01:27:11PM +0200, Greg Kroah-Hartman wrote:
> +	if (hcd->localmem_pool || !hcd_uses_dma(hcd)) {
> +		if (remap_pfn_range(vma, vma->vm_start,
> +				    virt_to_phys(usbm->mem) >> PAGE_SHIFT,
> +				    size, vma->vm_page_prot) < 0) {
> +			dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
> +			return -EAGAIN;
> +		}
> +	} else {
> +		if (dma_mmap_coherent(hcd->self.sysdev, vma, mem, dma_handle,
> +				      size)) {
> +			dec_usb_memory_use_count(usbm, &usbm->vma_use_count);
> +			return -EAGAIN;
> +		}

What about a goto label to share the error handling path?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>