On Fri, Dec 17, 2010 at 02:44:29PM -0800, rmorell@xxxxxxxxxx wrote: > On Fri, Dec 17, 2010 at 02:32:27PM -0800, Greg KH wrote: > > On Fri, Dec 17, 2010 at 01:58:47PM -0800, Robert Morell wrote: > > > This small set of patches fixes an issue where DMA from the tegra EHCI > > > controller could be corrupted. It was most commonly seen with USB network > > > adapters, though in theory it could happen with any USB traffic. > > > > > > (Note: An attempt was made to fix this with commit 367c3aab, which set > > > NET_IP_ALIGN to 0 and NET_SKB_PAD to 32. Unfortunately, not all network > > > drivers honor them (presumably since these are intended as optimizations rather > > > than hard rules). This does mean that properly-written network drivers should > > > fall through this code with very little overhead, however.) > > > > We don't have many USB network drivers, why not just fix them up to > > handle this properly, then you will not need to change any core USB > > code, right? > > The USB core code is used by devices other than USB adapters. We've > only seen this problem so far with usbnet devices, but I can't test > every USB device ever to make sure that they always align their DMA to > 32 bytes. Then it might just be easier for your driver to throw up a huge WARN_ON() if it detects such memory so that the device driver could be fixed, right? thanks, greg k-h -- 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
