bnx2: Flush the register writes which setup the MSI-X table

The MSI-X table size needs to be properly set before pci_enable_msix()
is called.  But on certain machines, the writes are delayed and the
MSI-X table size is incorrectly read.  By reading the
BNX2_PCI_MSIX_CONTROL register, the writes are flushed and now
ensure that the MSI-X table is set correctly before MSI-X
is enable on the device.

This patch was originally diagnosed and authored by
Kalyan Ram Chintalapati <kalyanc@vmware.com>.

Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: Kalyan Ram Chintalapati <kalyanc@vmware.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 65df1de447e4..b1c20e5f7de8 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -6145,6 +6145,10 @@ bnx2_enable_msix(struct bnx2 *bp, int msix_vecs)
         REG_WR(bp, BNX2_PCI_MSIX_TBL_OFF_BIR, BNX2_PCI_GRC_WINDOW2_BASE);
         REG_WR(bp, BNX2_PCI_MSIX_PBA_OFF_BIT, BNX2_PCI_GRC_WINDOW3_BASE);
 
+        /*  Need to flush the previous three writes to ensure MSI-X
+         *  is setup properly */
+        REG_RD(bp, BNX2_PCI_MSIX_CONTROL);
+
         for (i = 0; i < BNX2_MAX_MSIX_VEC; i++) {
                 msix_ent[i].entry = i;
                 msix_ent[i].vector = 0;