[3.16.y-ckt stable] Patch "tg3: tg3_disable_ints using uninitialized mailbox value to disable interrupts" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    tg3: tg3_disable_ints using uninitialized mailbox value to disable interrupts

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt5.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 550c08f3344da91dc0ed2e631d62e415fd0a6dd2 Mon Sep 17 00:00:00 2001
From: Prashant Sreedharan <prashant at broadcom.com>
Date: Sat, 20 Dec 2014 12:16:17 -0800
Subject: tg3: tg3_disable_ints using uninitialized mailbox value to disable
 interrupts

commit 05b0aa579397b734f127af58e401a30784a1e315 upstream.

During driver load in tg3_init_one, if the driver detects DMA activity before
intializing the chip tg3_halt is called. As part of tg3_halt interrupts are
disabled using routine tg3_disable_ints. This routine was using mailbox value
which was not initialized (default value is 0). As a result driver was writing
0x00000001 to pci config space register 0, which is the vendor id / device id.

This driver bug was exposed because of the commit a7877b17a667 (PCI: Check only
the Vendor ID to identify Configuration Request Retry). Also this issue is only
seen in older generation chipsets like 5722 because config space write to offset
0 from driver is possible. The newer generation chips ignore writes to offset 0.
Also without commit a7877b17a667, for these older chips when a GRC reset is
issued the Bootcode would reprogram the vendor id/device id, which is the reason
this bug was masked earlier.

Fixed by initializing the interrupt mailbox registers before calling tg3_halt.

Please queue for -stable.

Reported-by: Nils Holland <nholland at tisys.org>
Reported-by: Marcelo Ricardo Leitner <marcelo.leitner at gmail.com>
Signed-off-by: Prashant Sreedharan <prashant at broadcom.com>
Signed-off-by: Michael Chan <mchan at broadcom.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 2a1adec84d0e..73f7bdd1ebc9 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -17773,23 +17773,6 @@ static int tg3_init_one(struct pci_dev *pdev,
 		goto err_out_apeunmap;
 	}

-	/*
-	 * Reset chip in case UNDI or EFI driver did not shutdown
-	 * DMA self test will enable WDMAC and we'll see (spurious)
-	 * pending DMA on the PCI bus at that point.
-	 */
-	if ((tr32(HOSTCC_MODE) & HOSTCC_MODE_ENABLE) ||
-	    (tr32(WDMAC_MODE) & WDMAC_MODE_ENABLE)) {
-		tw32(MEMARB_MODE, MEMARB_MODE_ENABLE);
-		tg3_halt(tp, RESET_KIND_SHUTDOWN, 1);
-	}
-
-	err = tg3_test_dma(tp);
-	if (err) {
-		dev_err(&pdev->dev, "DMA engine test failed, aborting\n");
-		goto err_out_apeunmap;
-	}
-
 	intmbx = MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW;
 	rcvmbx = MAILBOX_RCVRET_CON_IDX_0 + TG3_64BIT_REG_LOW;
 	sndmbx = MAILBOX_SNDHOST_PROD_IDX_0 + TG3_64BIT_REG_LOW;
@@ -17834,6 +17817,23 @@ static int tg3_init_one(struct pci_dev *pdev,
 			sndmbx += 0xc;
 	}

+	/*
+	 * Reset chip in case UNDI or EFI driver did not shutdown
+	 * DMA self test will enable WDMAC and we'll see (spurious)
+	 * pending DMA on the PCI bus at that point.
+	 */
+	if ((tr32(HOSTCC_MODE) & HOSTCC_MODE_ENABLE) ||
+	    (tr32(WDMAC_MODE) & WDMAC_MODE_ENABLE)) {
+		tw32(MEMARB_MODE, MEMARB_MODE_ENABLE);
+		tg3_halt(tp, RESET_KIND_SHUTDOWN, 1);
+	}
+
+	err = tg3_test_dma(tp);
+	if (err) {
+		dev_err(&pdev->dev, "DMA engine test failed, aborting\n");
+		goto err_out_apeunmap;
+	}
+
 	tg3_init_coal(tp);

 	pci_set_drvdata(pdev, dev);
--
2.1.4