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

On Thu, May 14, 2020 at 01:58:29PM +0200, Christoph Hellwig wrote:

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?

I thought about that, but that's a bit messier than the duplicated lines here :)

Otherwise looks good:

Reviewed-by: Christoph Hellwig hch@lst.de

thanks for the review, and the help with this.

greg k-h