Bug in ks8851.c

[Max.Nekludov at us.elster.com]

Linus,

I tried to send the mail to 'Ben Dooks <ben at simtec.co.uk>' but the address
is dead now.
> I assume you've tested it in practice?
Yes, I'm running the modified code both in bootloader and Linux kernel on
my board.

Thanks,
Max

 Signed-off-by: Max Nekludov <Max.Nekludov at us.elster.com>
 ---
 drivers/net/ethernet/micrel/ks8851.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/micrel/ks8851.c
b/drivers/net/ethernet/micrel/ks8851.c
index 33bcb63d56a2..8fb481252e2c 100644
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -528,7 +528,7 @@ static void ks8851_rx_pkts(struct ks8851_net *ks)
 	for (; rxfc != 0; rxfc--) {
 		rxh = ks8851_rdreg32(ks, KS_RXFHSR);
 		rxstat = rxh & 0xffff;
-		rxlen = rxh >> 16;
+		rxlen = (rxh >> 16) & 0xfff;

 		netif_dbg(ks, rx_status, ks->netdev,
 			  "rx: stat 0x%04x, len 0x%04x\n", rxstat, rxlen);




Max,
 please cc the actual maintainers of the driver. The patch looks sane,
though. I assume you've tested it in practice?

You also seem to have based this on an ancient version, the code has
long since moved from drivers/net/ks8851.c to
drivers/net/ethernet/micrel/ks8851.c (back in June of 2011), and it's
missing a sign-off from you.

I'm attaching an updated patch for the rename/capitalization issue.

     Linus

On Thu, Mar 28, 2013 at 11:25 AM,  <Max.Nekludov at us.elster.com> wrote:
>
> According to the Datasheet (page 52):
> 15-12 Reserved
> 11-0 RXBC Receive Byte Count
> This field indicates the present received frame byte size.
>
> I suppose the code has a bug:
>                 rxh = ks8851_rdreg32(ks, KS_RXFHSR);
>                 rxstat = rxh & 0xffff;
>                 rxlen = rxh >> 16; // BUG!!! 0xFFF mask should be applied
>
> P.S.
> without bit mask applied I saw rxlen equal to 15360 which is bigger then
> entire RX queue size (12KB).
>
> Thanks,
> Max Nekludov
>
> From cb3199cee4490f98d6062e32a75ca377a32b55bc Mon Sep 17 00:00:00 2001
> From: Max Neklyudov <macscomp at gmail.com>
> Date: Tue, 26 Mar 2013 11:46:57 +0400
> Subject: [PATCH] Fix bug in ks8851 driver
>
> ---
>  drivers/net/ks8851.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ks8851.c b/drivers/net/ks8851.c
> index 91a93cb..0dc03da 100644
> --- a/drivers/net/ks8851.c
> +++ b/drivers/net/ks8851.c
> @@ -553,7 +553,7 @@ static void ks8851_rx_pkts(struct ks8851_net *ks)
>         for (; rxfc != 0; rxfc--) {
>                 rxh = ks8851_rdreg32(ks, KS_RXFHSR);
>                 rxstat = rxh & 0xffff;
> -               rxlen = rxh >> 16;
> +               rxlen = (rxh >> 16) & 0xFFF;
>
>                 netif_dbg(ks, rx_status, ks->netdev,
>                           "rx: stat 0x%04x, len 0x%04x\n", rxstat,
rxlen);
> --
> 1.7.10.4
>


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