On Wed, Mar 03, 2010 at 12:31:32PM +0000, Catalin Marinas wrote: > Hi Greg, > > 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... 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
