Re: [PATCH RESEND] dm9601: don't do usb transfers of data on stack
From: Oliver Neukum <hidden>
Date: 2008-07-11 12:00:37
From: Oliver Neukum <hidden>
Date: 2008-07-11 12:00:37
Am Freitag 11 Juli 2008 13:37:39 schrieb Peter Korsgaard:
dm_{read,write}_shared_word() were doing USB transfers of data on stack,
which isn't allowed. Fix it by using the usbnet->data area like in
dm9601_set_multicast().You cannot do this. You've identified the bug correctly, but the fix is incorrect. Doing DMA on non coherent architectures means that any cacheline the buffer shares must not be touched while DMA may be running. If you embed the buffer into struct usbnet, how could you meet the guarantee? Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html