From: Alan Stern > On Fri, 7 Mar 2014, David Laight wrote: > > > From: Mathias Nyman > > > This reverts commit 3804fad45411b48233b48003e33a78f290d227c8. > > > > > > This commit, together with commit 247bf557273dd775505fb9240d2d152f4f20d304 > > > "xhci 1.0: Limit arbitrarily-aligned scatter gather." were > > > origially added to get xHCI 1.0 hosts and usb ethernet ax88179_178a devices > > > working together with scatter gather. xHCI 1.0 hosts pose some requirement on how transfer > > > buffers are aligned, setting this requirement for 1.0 hosts caused USB 3.0 mass > > > storage devices to fail more frequently. > > > > This patch doesn't need to be reverted. > > Yes, it does. > > > Provided the xhci driver doesn't set the flag to say that arbitrary scatter > > gather is supported (ie usb_device_no_sg_constraint(dev->udev)) is false) > > the ax88179_178a driver won't request transmits that need fragmenting. > > True. But xhci-hcd _will_ set the flag, because of patch 1 in this > series. In other words, patch 1 makes patch 2 necessary. I was reading patch 2 first. It would seem to be better to modify patch 1 - so it doesn't set the flag. Then the changes are limited to the usb tree, and the change to net wouldn't need to be reapplied in order to test scatter-gather when it is properly fixed. David -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
