tg3: tg3_disable_ints using uninitialized mailbox value to disable interrupts

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>

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index bb48a61..553dcd8 100644 (file)
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -17800,23 +17800,6 @@ 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;
@@ -17861,6 +17844,23 @@ 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);