On Thu, 2010-03-04 at 02:54 +0000, Greg KH wrote: > On Wed, Mar 03, 2010 at 12:31:32PM +0000, Catalin Marinas wrote: > > On Tue, 2010-03-02 at 23:38 +0000, Greg Kroah-Hartman wrote: > > > When the HDC driver writes the data to the transfer buffers it pollutes > > > the D-cache (unlike DMA drivers where the device writes the data). If > > > the corresponding pages get mapped into user space, there are no > > > additional cache flushing operations performed and this causes random > > > user space faults on architectures with separate I and D caches > > > (Harvard) or those with aliasing D-cache. > > > > Following the recent discussions in this thread (USB HCD and ARM cache > > coherency): > > > > http://thread.gmane.org/gmane.linux.usb.general/27072 > > > > we may no longer need this patch but change the ARM cache handling to > > assume that any newly allocated page cache page is dirty by default (and > > the PG_arch_1 bit actually meaning clean rather than dirty). > > > > I think it would be better not to push this to mainline until we clarify > > this in the ARM land. > > Hm, it's a bit late now :) > > If you don't need it, care to send me a patch to revert it as it is in > Linus's tree at the moment... OK, no problem. It currently allows the ARM port to work correclty with this driver. Once we modify the cache flushing (still under discussion), I'll send a patch to revert this commit. Thanks. -- Catalin -- 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
