tg3: Disable CLKREQ in L2

This patch disables CLKREQ in L2 to workaround a chipset bug.

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

2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 460a0c22b318..4ae01b3799f4 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -7642,6 +7642,20 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
                 tw32(GRC_MODE, grc_mode);
         }
 
+        if (tp->pci_chip_rev_id == CHIPREV_ID_57765_A0) {
+                u32 grc_mode = tr32(GRC_MODE);
+
+                /* Access the lower 1K of PL PCIE block registers. */
+                val = grc_mode & ~GRC_MODE_PCIE_PORT_MASK;
+                tw32(GRC_MODE, val | GRC_MODE_PCIE_PL_SEL);
+
+                val = tr32(TG3_PCIE_TLDLPL_PORT + TG3_PCIE_PL_LO_PHYCTL5);
+                tw32(TG3_PCIE_TLDLPL_PORT + TG3_PCIE_PL_LO_PHYCTL5,
+                     val | TG3_PCIE_PL_LO_PHYCTL5_DIS_L2CLKREQ);
+
+                tw32(GRC_MODE, grc_mode);
+        }
+
         /* This works around an issue with Athlon chipsets on
          * B3 tigon3 silicon.  This bit has no effect on any
          * other revision.  But do not set this on PCI Express
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 5d7f72a2ea01..8a6012ab23ff 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -1854,6 +1854,8 @@
 #define TG3_PCIE_TLDLPL_PORT            0x00007c00
 #define TG3_PCIE_PL_LO_PHYCTL1           0x00000004
 #define TG3_PCIE_PL_LO_PHYCTL1_L1PLLPD_EN         0x00001000
+#define TG3_PCIE_PL_LO_PHYCTL5           0x00000014
+#define TG3_PCIE_PL_LO_PHYCTL5_DIS_L2CLKREQ       0x80000000
 
 /* OTP bit definitions */
 #define TG3_OTP_AGCTGT_MASK             0x000000e0