Re: How to resolve an issue in swiotlb environment?

Greg KH
2019-06-13T18:18:22Z

On Thu, Jun 13, 2019 at 01:16:32PM -0400, Alan Stern wrote:
> On Thu, 13 Jun 2019, Christoph Hellwig wrote:
>
> > On Wed, Jun 12, 2019 at 10:43:11AM -0400, Alan Stern wrote:
> > > Would it be okay to rely on the assumption that USB block devices never
> > > have block size < 512? (We could even add code to the driver to
> > > enforce this, although refusing to handle such devices at all might be
> > > worse than getting an occasional error.)
> >
> > sd.c only supports a few specific sector size, and none of them is
> > < 512 bytes:
> >
> > if (sector_size != 512 &&
> > sector_size != 1024 &&
> > sector_size != 2048 &&
> > sector_size != 4096) {
> > ...
> > sdkp->capacity = 0;
>
> Great! So all we have to do is fix vhci-hcd. Then we can remove all
> the virt_boundary_mask stuff from usb-storage and uas entirely.
>
> (I'm assuming wireless USB isn't a genuine issue. As far as I know, it
> is pretty much abandoned at this point.)

It is, I need to just move it to staging and delete the thing. I don't
know of any hardware anymore.

thanks,

greg k-h