On Mon, Oct 21, 2019 at 11:48:06AM -0400, Alan Stern wrote:
> There is no longer any reason to keep the virt_boundary_mask setting
> for usb-storage. It was needed in the first place only for handling
> devices with a block size smaller than the maxpacket size and where
> the host controller was not capable of fully general scatter-gather
> operation (that is, able to merge two SG segments into a single USB
> packet). But:
>
> High-speed or slower connections never use a bulk maxpacket
> value larger than 512;
>
> The SCSI layer does not handle block devices with a block size
> smaller than 512 bytes;
>
> All the host controllers capable of SuperSpeed operation can
> handle fully general SG;
>
> Since commit ea44d190764b ("usbip: Implement SG support to
> vhci-hcd and stub driver") was merged, the USB/IP driver can
> also handle SG.
>
> Therefore all supported device/controller combinations should be okay
> with no need for any special virt_boundary_mask. So in order to fix
> the swiotlb problem, this patch reverts commit 747668dbc061.
That's great to know. The same should also apply to uas, shouldn't
it?
Otherwise:
Acked-by: Christoph Hellwig <hch@xxxxxx>
