[PATCH v2 2/2] bnx2: Wait for in-flight DMA to complete at probe stage

[Baoquan He]

In-flight DMA from 1st kernel could continue going in kdump kernel.
New io-page table has been created before bnx2 does reset at open stage.
We have to wait for the in-flight DMA to complete to avoid it look up
into the newly created io-page table at probe stage.

Suggested-by: Michael Chan <michael.c...@broadcom.com>
Signed-off-by: Baoquan He <b...@redhat.com>
---
 drivers/net/ethernet/broadcom/bnx2.c | 38 ++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2.c 
b/drivers/net/ethernet/broadcom/bnx2.c
index c557972..1f7034d 100644
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -49,6 +49,7 @@
 #include <linux/firmware.h>
 #include <linux/log2.h>
 #include <linux/aer.h>
+#include <linux/crash_dump.h>
 
 #if IS_ENABLED(CONFIG_CNIC)
 #define BCM_CNIC 1
@@ -4764,15 +4765,16 @@ bnx2_setup_msix_tbl(struct bnx2 *bp)
        BNX2_WR(bp, BNX2_PCI_GRC_WINDOW3_ADDR, BNX2_MSIX_PBA_ADDR);
 }
 
-static int
-bnx2_reset_chip(struct bnx2 *bp, u32 reset_code)
+static void
+bnx2_wait_dma_complete(struct bnx2 *bp)
 {
        u32 val;
-       int i, rc = 0;
-       u8 old_port;
+       int i;
 
-       /* Wait for the current PCI transaction to complete before
-        * issuing a reset. */
+       /*
+        * Wait for the current PCI transaction to complete before
+        * issuing a reset.
+        */
        if ((BNX2_CHIP(bp) == BNX2_CHIP_5706) ||
            (BNX2_CHIP(bp) == BNX2_CHIP_5708)) {
                BNX2_WR(bp, BNX2_MISC_ENABLE_CLR_BITS,
@@ -4796,6 +4798,21 @@ bnx2_reset_chip(struct bnx2 *bp, u32 reset_code)
                }
        }
 
+       return;
+}
+
+
+static int
+bnx2_reset_chip(struct bnx2 *bp, u32 reset_code)
+{
+       u32 val;
+       int i, rc = 0;
+       u8 old_port;
+
+       /* Wait for the current PCI transaction to complete before
+        * issuing a reset. */
+       bnx2_wait_dma_complete(bp);
+
        /* Wait for the firmware to tell us it is ok to issue a reset. */
        bnx2_fw_sync(bp, BNX2_DRV_MSG_DATA_WAIT0 | reset_code, 1, 1);
 
@@ -8580,6 +8597,15 @@ bnx2_init_one(struct pci_dev *pdev, const struct 
pci_device_id *ent)
 
        pci_set_drvdata(pdev, dev);
 
+       /*
+        * In-flight DMA from 1st kernel could continue going in kdump kernel.
+        * New io-page table has been created before bnx2 does reset at open 
stage.
+        * We have to wait for the in-flight DMA to complete to avoid it look up
+        * into the newly created io-page table.
+        */
+       if (is_kdump_kernel())
+               bnx2_wait_dma_complete(bp);
+
        memcpy(dev->dev_addr, bp->mac_addr, ETH_ALEN);
 
        dev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG |
-- 
2.5.5