>>>>> "Johannes" == Johannes Erdfelt <[EMAIL PROTECTED]> writes:
Johannes> All of the uses of usb_get_descriptor in usb.c are
Johannes> safe. I'd much rather make the calling routine require a
Johannes> DMA capable buffer than in usb_get_descriptor.
I just looked back at usb.c. Some of the calls to
usb_get_descriptor() look like
int ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor,
sizeof(dev->descriptor));
I'm not convinced that such a call is safe in all circumstances.
dev->descriptor is smaller than a cache line and is not cache line
aligned. When pci_map_single() finally gets called with address it
will invalidate the whole cache line, which could cause problems if
adjacent members of dev are accessed.
Is this reasoning correct or do you think it's better to leave that
code as-is?
Thanks,
Roland
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