2013-03-28 18:37:20

by Max.Nekludov

[permalink] [raw]
Subject: Bug in ks8851.c



----- Forwarded by Max Nekludov/USE/Elster on 28.03.2013 22:29 -----
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|Max Nekludov/USE/Elster |
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|[email protected] |
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|[email protected], [email protected] |
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|28.03.2013 22:25 |
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|Bug in ks8851.c |
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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 <[email protected]>
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