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

From: Larry Finger
Date: Mon Dec 26 2011 - 13:32:25 EST

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+

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.


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);
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.


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