tg3: Fix 5719 internal FIFO overflow problem

Under load, there an internal FIFO can overflow on the 5719.  The fix is
to scale back the PCIe maximum read request size based on the current
link speed and width.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 2624d714d16ee6fd6784079077ad50e599d648d5..226e60dfaeaf41dcdc05dabeada3ce0d34542ddc 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -6985,7 +6985,7 @@ static void tg3_restore_pci_state(struct tg3 *tp)
 
        if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5785) {
                if (tp->tg3_flags2 & TG3_FLG2_PCI_EXPRESS)
-                       pcie_set_readrq(tp->pdev, 4096);
+                       pcie_set_readrq(tp->pdev, tp->pcie_readrq);
                else {
                        pci_write_config_byte(tp->pdev, PCI_CACHE_LINE_SIZE,
                                              tp->pci_cacheline_sz);
@@ -7179,7 +7179,7 @@ static int tg3_chip_reset(struct tg3 *tp)
                                      tp->pcie_cap + PCI_EXP_DEVCTL,
                                      val16);
 
-               pcie_set_readrq(tp->pdev, 4096);
+               pcie_set_readrq(tp->pdev, tp->pcie_readrq);
 
                /* Clear error status */
                pci_write_config_word(tp->pdev,
@@ -13366,7 +13366,45 @@ static int __devinit tg3_get_invariants(struct tg3 *tp)
 
                tp->tg3_flags2 |= TG3_FLG2_PCI_EXPRESS;
 
-               pcie_set_readrq(tp->pdev, 4096);
+               tp->pcie_readrq = 4096;
+               if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5719) {
+                       u16 word;
+
+                       pci_read_config_word(tp->pdev,
+                                            tp->pcie_cap + PCI_EXP_LNKSTA,
+                                            &word);
+                       switch (word & PCI_EXP_LNKSTA_CLS) {
+                       case PCI_EXP_LNKSTA_CLS_2_5GB:
+                               word &= PCI_EXP_LNKSTA_NLW;
+                               word >>= PCI_EXP_LNKSTA_NLW_SHIFT;
+                               switch (word) {
+                               case 2:
+                                       tp->pcie_readrq = 2048;
+                                       break;
+                               case 4:
+                                       tp->pcie_readrq = 1024;
+                                       break;
+                               }
+                               break;
+
+                       case PCI_EXP_LNKSTA_CLS_5_0GB:
+                               word &= PCI_EXP_LNKSTA_NLW;
+                               word >>= PCI_EXP_LNKSTA_NLW_SHIFT;
+                               switch (word) {
+                               case 1:
+                                       tp->pcie_readrq = 2048;
+                                       break;
+                               case 2:
+                                       tp->pcie_readrq = 1024;
+                                       break;
+                               case 4:
+                                       tp->pcie_readrq = 512;
+                                       break;
+                               }
+                       }
+               }
+
+               pcie_set_readrq(tp->pdev, tp->pcie_readrq);
 
                pci_read_config_word(tp->pdev,
                                     tp->pcie_cap + PCI_EXP_LNKCTL,

diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 06a4e7e8fff395d9041487b3c249d33728b9efee..410703684e39855cc09a76015c46771d6a419828 100644 (file)
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2948,6 +2948,7 @@ struct tg3 {
        int                             pcix_cap;
        int                             pcie_cap;
        };
+       int                             pcie_readrq;
 
        struct mii_bus                  *mdio_bus;
        int                             mdio_irq[PHY_MAX_ADDR];