From: Oliver Neukum <oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
To: Peter Korsgaard <jacmet-OfajU3CKLf1/SzgSGea1oA@public.gmane.org>
Cc: jeff-o2qLIJkoznsdnm+yROfE0A@public.gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH RESEND] dm9601: don't do usb transfers of data on stack
Date: Fri, 11 Jul 2008 14:00:37 +0200 [thread overview]
Message-ID: <200807111400.38312.oliver@neukum.org> (raw)
In-Reply-To: <87mykoircs.fsf-uXGAPMMVk8amE9MCos8gUmSdvHPH+/yF@public.gmane.org>
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
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next prev parent reply other threads:[~2008-07-11 12:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-11 11:37 [PATCH RESEND] dm9601: don't do usb transfers of data on stack Peter Korsgaard
[not found] ` <87mykoircs.fsf-uXGAPMMVk8amE9MCos8gUmSdvHPH+/yF@public.gmane.org>
2008-07-11 12:00 ` Oliver Neukum [this message]
[not found] ` <200807111400.38312.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2008-07-11 12:17 ` Peter Korsgaard
2008-07-11 12:22 ` Oliver Neukum
[not found] ` <200807111422.56406.oliver-GvhC2dPhHPQdnm+yROfE0A@public.gmane.org>
2008-07-11 12:55 ` Peter Korsgaard
2008-07-11 12:57 ` Peter Korsgaard
[not found] ` <87mykoefy4.fsf-uXGAPMMVk8amE9MCos8gUmSdvHPH+/yF@public.gmane.org>
2008-07-11 22:02 ` David Brownell
[not found] ` <200807111502.20507.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-07-14 7:07 ` Peter Korsgaard
[not found] ` <87wsjp9c5n.fsf-uXGAPMMVk8amE9MCos8gUmSdvHPH+/yF@public.gmane.org>
2008-07-30 8:48 ` Jeff Garzik
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