[PATCH] tg3: Fix INTx fallback when MSI fails

[Andre Detsch <adetsch@br.ibm.com>]

tg3: Fix INTx fallback when MSI fails

MSI setup changes the value of some key attributes of struct tg3 *tp.
These attributes must be taken into account and restored before
we try to do a new request_irq for INTx fallback.

In powerpc, the original code was leading to an EINVAL return within
request_irq, because the driver was trying to use the disabled MSI
virtual irq number instead of tp->pdev->irq.

Signed-off-by: Andre Detsch <adetsch@br.ibm.com>

---
Tested on powerpc, but should be safe for other architectures as well.

Index: linux-2.6.34-rc4/drivers/net/tg3.c
===================================================================
--- linux-2.6.34-rc4.orig/drivers/net/tg3.c	2010-04-12 21:41:35.000000000 -0400
+++ linux-2.6.34-rc4/drivers/net/tg3.c	2010-04-15 20:37:41.000000000 -0400
@@ -8633,6 +8633,9 @@ static int tg3_test_msi(struct tg3 *tp)
 	pci_disable_msi(tp->pdev);

 	tp->tg3_flags2 &= ~TG3_FLG2_USING_MSI;
+	tp->irq_cnt = 1;
+	tp->napi[0].irq_vec = tp->pdev->irq;
+	tp->dev->real_num_tx_queues = 1;

 	err = tg3_request_irq(tp, 0);
 	if (err)