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Message-ID: <20080416201759.GB19724@localdomain>
Date: Wed, 16 Apr 2008 13:17:59 -0700
From: "Matt Carlson" <mcarlson@...adcom.com>
To: tonyb@...ernetics.com
cc: "David Miller" <davem@...emloft.net>,
"Michael Chan" <mchan@...adcom.com>,
"Matthew Carlson" <mcarlson@...adcom.com>,
herbert@...dor.apana.org.au, netdev@...r.kernel.org,
gregkh@...e.de, linux-kernel@...r.kernel.org
Subject: Re: TG3 network data corruption regression 2.6.24/2.6.23.4
On Wed, Apr 16, 2008 at 08:40:25AM -0700, Michael Chan wrote:
> David Miller wrote:
>
> > Matt, skb->mac_header is either a pointer or an integer offset
> > depending upon whether we are building 32-bit or 64-bit.
> >
> > Testing skb->mac_header is therefore wrong, because it's an
> > offset from a pointer in the 64-bit case and therefore it's
> > alignment does not indicate correctly the actual final alignment
> > of skb->head + skb->max_header.
> >
> > Therefore you should test skb_mac_header(skb) and cast it with
> > (unsigned long).
>
> Isn't it better to test for skb->data? That's where we tell
> the hardware to start transmitting.
>
> >
> > Please respin this fix with that correction so I can apply it
> > and get this bug fixed, thanks!
> >
> >
>
> We think that this problem is unique in Tony's environment because
> of the PCIE-to-PCI bridge that he is using. We therefore want to
> test for that bridge and apply the workaround only when it's present.
> We've never seen this problem in the last 6 or 7 years during the
> lifetime of the 5701.
>
> We'll try to get this done ASAP.
>
> Thanks.
Tony,
Below is a patch that attempts to limit the workaround to the bridge you
have on your system. Can you test it and verify that the workaround is
still enabled?
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 96043c5..52a44c6 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4135,11 +4135,21 @@ static int tigon3_dma_hwbug_workaround(struct tg3 *tp, struct sk_buff *skb,
u32 last_plus_one, u32 *start,
u32 base_flags, u32 mss)
{
- struct sk_buff *new_skb = skb_copy(skb, GFP_ATOMIC);
+ struct sk_buff *new_skb;
dma_addr_t new_addr = 0;
u32 entry = *start;
int i, ret = 0;
+ if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701)
+ new_skb = skb_copy(skb, GFP_ATOMIC);
+ else {
+ int more_headroom = 4 - ((unsigned long)skb->data & 3);
+
+ new_skb = skb_copy_expand(skb,
+ skb_headroom(skb) + more_headroom,
+ skb_tailroom(skb), GFP_ATOMIC);
+ }
+
if (!new_skb) {
ret = -1;
} else {
@@ -4462,7 +4472,9 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev)
would_hit_hwbug = 0;
- if (tg3_4g_overflow_test(mapping, len))
+ if (tp->tg3_flags3 & TG3_FLG3_5701_DMA_BUG)
+ would_hit_hwbug = 1;
+ else if (tg3_4g_overflow_test(mapping, len))
would_hit_hwbug = 1;
tg3_set_txd(tp, entry, mapping, len, base_flags,
@@ -11339,6 +11351,41 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
}
}
+ if ((GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5701)) {
+ static struct tg3_dev_id {
+ u32 vendor;
+ u32 device;
+ } bridge_chipsets[] = {
+ { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PXH_0 },
+ { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PXH_1 },
+ { },
+ };
+ struct tg3_dev_id *pci_id = &bridge_chipsets[0];
+ struct pci_dev *bridge = NULL;
+
+ while (pci_id->vendor != 0 &&
+ !(tp->tg3_flags3 & TG3_FLG3_5701_DMA_BUG)) {
+ while (1) {
+ bridge = pci_get_device(pci_id->vendor,
+ pci_id->device,
+ bridge);
+ if (!bridge) {
+ pci_id++;
+ break;
+ }
+ if (bridge->subordinate &&
+ (bridge->subordinate->number <=
+ tp->pdev->bus->number) &&
+ (bridge->subordinate->subordinate >=
+ tp->pdev->bus->number)) {
+ tp->tg3_flags3 |= TG3_FLG3_5701_DMA_BUG;
+ pci_dev_put(bridge);
+ break;
+ }
+ }
+ }
+ }
+
/* The EPB bridge inside 5714, 5715, and 5780 cannot support
* DMA addresses > 40-bit. This bridge may have other additional
* 57xx devices behind it in some 4-port NIC designs for example.
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index c1075a7..c688c3a 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2476,6 +2476,7 @@ struct tg3 {
#define TG3_FLG3_NO_NVRAM_ADDR_TRANS 0x00000001
#define TG3_FLG3_ENABLE_APE 0x00000002
#define TG3_FLG3_5761_5784_AX_FIXES 0x00000004
+#define TG3_FLG3_5701_DMA_BUG 0x00000008
struct timer_list timer;
u16 timer_counter;
--
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