Re: [PATCH] b43: fix regression in PIO case

[Larry Finger]

On 12/26/2011 12:17 PM, Guennadi Liakhovetski wrote:
> On Mon, 26 Dec 2011, Larry Finger wrote:
>
> > On 12/26/2011 11:28 AM, Guennadi Liakhovetski wrote:
> > > This patch fixes the regression, introduced by
> > >
> > > commit 17030f48e31adde5b043741c91ba143f5f7db0fd
> > > From: Rafał Miłecki<zajec5@xxxxxxxxx>
> > > Date: Thu, 11 Aug 2011 17:16:27 +0200
> > > Subject: [PATCH] b43: support new RX header, noticed to be used in 598.314+
> > > fw
> > >
> > > in PIO case.
> > >
> > > Signed-off-by: Guennadi Liakhovetski<g.liakhovetski@xxxxxx>
> > > ---
> > > diff --git a/drivers/net/wireless/b43/pio.c b/drivers/net/wireless/b43/pio.c
> > > index ce8a4bd..b64b64c 100644
> > > --- a/drivers/net/wireless/b43/pio.c
> > > +++ b/drivers/net/wireless/b43/pio.c
> > > @@ -617,9 +617,19 @@ static bool pio_rx_frame(struct b43_pio_rxqueue *q)
> > >    	const char *err_msg = NULL;
> > >    	struct b43_rxhdr_fw4 *rxhdr =
> > >    		(struct b43_rxhdr_fw4 *)wl->pio_scratchspace;
> > > +	size_t rxhdr_size = sizeof(*rxhdr);
> > >
> > >    	BUILD_BUG_ON(sizeof(wl->pio_scratchspace)<   sizeof(*rxhdr));
> > > -	memset(rxhdr, 0, sizeof(*rxhdr));
> > > +	switch (dev->fw.hdr_format) {
> > > +	case B43_FW_HDR_410:
> > > +	case B43_FW_HDR_351:
> > > +		rxhdr_size -= sizeof(rxhdr->format_598) -
> > > +			sizeof(rxhdr->format_351);
> > > +		break;
> > > +	case B43_FW_HDR_598:
> > > +		break;
> > > +	}
> >
> > I do not think the above will work for format_410. By my count, the format_410
> > struct is 4 bytes longer than the format_351 struct.
>
> I think you're looking at struct b43_txhdr, whereas the problem is in
> struct b43_rxhdr_fw4.
>
> Thanks
> Guennadi
>
> > Even if it does work, I suggest using the following:
> >
> > 	size_t rxhdr_size;
> >
> >     	BUILD_BUG_ON(sizeof(wl->pio_scratchspace)<   sizeof(*rxhdr));
> > 	switch (dev->fw.hdr_format) {
> > 	case B43_FW_HDR_351:
> > 		rxhdr_size = sizeof(rxhdr->format_351);
> > 		break;
> > 	case B43_FW_HDR_410:

You are correct - I was looking in the wrong place. Even so, I prefer setting 
rxhdr_size in the case branches, and not adjust one preset earlier.

Larry

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/