[PATCH 3.14 05/98] tg3: tg3_disable_ints using uninitialized mailbox value to disable interrupts

Greg Kroah-Hartman
2015-01-25T19:27:27Z

From: Prashant Sreedharan <prashant@broadcom.com>

[ Upstream commit 05b0aa579397b734f127af58e401a30784a1e315 ]

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@tisys.org>
Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Prashant Sreedharan <prashant@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/broadcom/tg3.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)

--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -17731,23 +17731,6 @@ static int tg3_init_one(struct pci_dev *
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;
@@ -17792,6 +17775,23 @@ static int tg3_init_one(struct pci_dev *
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);