On Mon, Feb 01, 2010 at 05:29:14PM +0000, Catalin Marinas wrote: > On Fri, 2010-01-29 at 18:54 +0000, Matthew Dharm wrote: > > HOWEVER, I firmly believe that the cache-management functions belong with > > the driver that actually talks to the low-level hardware, as that's the > > only place where you can be 100% certain of what cache operations are > > needed. After all, I think someone is working on a USB-over-IP transport, > > and trying to manage cache at the usb-storage level in that scenario is > > just silly. > > > > So, let's put this in the HCD drivers and be done with it. > > The patch below is what fixes the I-D cache incoherency issues on ARM. I > don't particularly like the solution but it seems to be the only one > available. > > IMHO, Linux should have functions similar to the DMA API but for PIO > drivers (e.g. pio_map_single/pio_unmap_single) that non-coherent > architectures can define, otherwise being no-ops. Any thoughts? > I would certainly be in favour of such a thing, particularly since on SH we often find ourselves with coherent PIO and non-coherent MMIO. This is however something that should be prototyped and submitted to linux-arch for discussion. > diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c > index 27b8f7c..4d3eeee 100644 > --- a/drivers/usb/host/isp1760-hcd.c > +++ b/drivers/usb/host/isp1760-hcd.c > @@ -18,6 +18,8 @@ > #include <linux/uaccess.h> > #include <linux/io.h> > #include <asm/unaligned.h> > +#include <asm/cacheflush.h> > +#include <asm/memory.h> > asm/memory.h isn't a portable header. If you are including it for virt_to_page(), linux/io.h should already bring that in via asm/io.h. If arm doesn't bring in virt_to_page() through its asm/io.h, then fix the headers there please. FWIW I used the same fix you came up with on r8a66597_hcd and it fixed up crashes we were seeing there, too. -- 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
