[TG3]: Add tw32_wait_f() for some sensitive registers

The tw32_f() function (register write with immediate read flush) can
hang when used on some registers to switch clock frequencies and
power. A new tw32_wait_f() is added for such registers with the
delay before the read and after the read.

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

1 files changed, 77 insertions, 74 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index de898f175d7..b0d963c8374 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -341,6 +341,16 @@ static struct {
         { "interrupt test (offline)" },
 };
 
+static void tg3_write32(struct tg3 *tp, u32 off, u32 val)
+{
+        writel(val, tp->regs + off);
+}
+
+static u32 tg3_read32(struct tg3 *tp, u32 off)
+{
+        return (readl(tp->regs + off)); 
+}
+
 static void tg3_write_indirect_reg32(struct tg3 *tp, u32 off, u32 val)
 {
         unsigned long flags;
@@ -411,13 +421,29 @@ static u32 tg3_read_indirect_mbox(struct tg3 *tp, u32 off)
         return val;
 }
 
-static void _tw32_flush(struct tg3 *tp, u32 off, u32 val)
+/* usec_wait specifies the wait time in usec when writing to certain registers
+ * where it is unsafe to read back the register without some delay.
+ * GRC_LOCAL_CTRL is one example if the GPIOs are toggled to switch power.
+ * TG3PCI_CLOCK_CTRL is another example if the clock frequencies are changed.
+ */
+static void _tw32_flush(struct tg3 *tp, u32 off, u32 val, u32 usec_wait)
 {
-        tp->write32(tp, off, val);
-        if (!(tp->tg3_flags & TG3_FLAG_PCIX_TARGET_HWBUG) &&
-            !(tp->tg3_flags & TG3_FLAG_5701_REG_WRITE_BUG) &&
-            !(tp->tg3_flags2 & TG3_FLG2_ICH_WORKAROUND))
-                tp->read32(tp, off);    /* flush */
+        if ((tp->tg3_flags & TG3_FLAG_PCIX_TARGET_HWBUG) ||
+            (tp->tg3_flags2 & TG3_FLG2_ICH_WORKAROUND))
+                /* Non-posted methods */
+                tp->write32(tp, off, val);
+        else {
+                /* Posted method */
+                tg3_write32(tp, off, val);
+                if (usec_wait)
+                        udelay(usec_wait);
+                tp->read32(tp, off);
+        }
+        /* Wait again after the read for the posted method to guarantee that
+         * the wait time is met.
+         */
+        if (usec_wait)
+                udelay(usec_wait);
 }
 
 static inline void tw32_mailbox_flush(struct tg3 *tp, u32 off, u32 val)
@@ -438,16 +464,6 @@ static void tg3_write32_tx_mbox(struct tg3 *tp, u32 off, u32 val)
                 readl(mbox);
 }
 
-static void tg3_write32(struct tg3 *tp, u32 off, u32 val)
-{
-        writel(val, tp->regs + off);
-}
-
-static u32 tg3_read32(struct tg3 *tp, u32 off)
-{
-        return (readl(tp->regs + off)); 
-}
-
 #define tw32_mailbox(reg, val)  tp->write32_mbox(tp, reg, val)
 #define tw32_mailbox_f(reg, val)        tw32_mailbox_flush(tp, (reg), (val))
 #define tw32_rx_mbox(reg, val)  tp->write32_rx_mbox(tp, reg, val)
@@ -455,7 +471,8 @@ static u32 tg3_read32(struct tg3 *tp, u32 off)
 #define tr32_mailbox(reg)       tp->read32_mbox(tp, reg)
 
 #define tw32(reg,val)           tp->write32(tp, reg, val)
-#define tw32_f(reg,val)         _tw32_flush(tp,(reg),(val))
+#define tw32_f(reg,val)         _tw32_flush(tp,(reg),(val), 0)
+#define tw32_wait_f(reg,val,us) _tw32_flush(tp,(reg),(val), (us))
 #define tr32(reg)               tp->read32(tp, reg)
 
 static void tg3_write_mem(struct tg3 *tp, u32 off, u32 val)
@@ -595,21 +612,19 @@ static void tg3_switch_clocks(struct tg3 *tp)
 
         if (tp->tg3_flags2 & TG3_FLG2_5705_PLUS) {
                 if (orig_clock_ctrl & CLOCK_CTRL_625_CORE) {
-                        tw32_f(TG3PCI_CLOCK_CTRL,
-                               clock_ctrl | CLOCK_CTRL_625_CORE);
-                        udelay(40);
+                        tw32_wait_f(TG3PCI_CLOCK_CTRL,
+                                    clock_ctrl | CLOCK_CTRL_625_CORE, 40);
                 }
         } else if ((orig_clock_ctrl & CLOCK_CTRL_44MHZ_CORE) != 0) {
-                tw32_f(TG3PCI_CLOCK_CTRL,
-                     clock_ctrl |
-                     (CLOCK_CTRL_44MHZ_CORE | CLOCK_CTRL_ALTCLK));
-                udelay(40);
-                tw32_f(TG3PCI_CLOCK_CTRL,
-                     clock_ctrl | (CLOCK_CTRL_ALTCLK));
-                udelay(40);
+                tw32_wait_f(TG3PCI_CLOCK_CTRL,
+                            clock_ctrl |
+                            (CLOCK_CTRL_44MHZ_CORE | CLOCK_CTRL_ALTCLK),
+                            40);
+                tw32_wait_f(TG3PCI_CLOCK_CTRL,
+                            clock_ctrl | (CLOCK_CTRL_ALTCLK),
+                            40);
         }
-        tw32_f(TG3PCI_CLOCK_CTRL, clock_ctrl);
-        udelay(40);
+        tw32_wait_f(TG3PCI_CLOCK_CTRL, clock_ctrl, 40);
 }
 
 #define PHY_BUSY_LOOPS  5000
@@ -1033,13 +1048,13 @@ static void tg3_frob_aux_power(struct tg3 *tp)
             (tp_peer->tg3_flags & TG3_FLAG_ENABLE_ASF) != 0) {
                 if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5700 ||
                     GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5701) {
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                             (GRC_LCLCTRL_GPIO_OE0 |
-                              GRC_LCLCTRL_GPIO_OE1 |
-                              GRC_LCLCTRL_GPIO_OE2 |
-                              GRC_LCLCTRL_GPIO_OUTPUT0 |
-                              GRC_LCLCTRL_GPIO_OUTPUT1));
-                        udelay(100);
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                    (GRC_LCLCTRL_GPIO_OE0 |
+                                     GRC_LCLCTRL_GPIO_OE1 |
+                                     GRC_LCLCTRL_GPIO_OE2 |
+                                     GRC_LCLCTRL_GPIO_OUTPUT0 |
+                                     GRC_LCLCTRL_GPIO_OUTPUT1),
+                                    100);
                 } else {
                         u32 no_gpio2;
                         u32 grc_local_ctrl = 0;
@@ -1052,9 +1067,8 @@ static void tg3_frob_aux_power(struct tg3 *tp)
                         if (GET_ASIC_REV(tp->pci_chip_rev_id) ==
                             ASIC_REV_5714) {
                                 grc_local_ctrl |= GRC_LCLCTRL_GPIO_OE3;
-                                tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                                       grc_local_ctrl);
-                                udelay(100);
+                                tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                            grc_local_ctrl, 100);
                         }
 
                         /* On 5753 and variants, GPIO2 cannot be used. */
@@ -1070,21 +1084,18 @@ static void tg3_frob_aux_power(struct tg3 *tp)
                                 grc_local_ctrl &= ~(GRC_LCLCTRL_GPIO_OE2 |
                                                     GRC_LCLCTRL_GPIO_OUTPUT2);
                         }
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                                                grc_local_ctrl);
-                        udelay(100);
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                                    grc_local_ctrl, 100);
 
                         grc_local_ctrl |= GRC_LCLCTRL_GPIO_OUTPUT0;
 
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                                                grc_local_ctrl);
-                        udelay(100);
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                                    grc_local_ctrl, 100);
 
                         if (!no_gpio2) {
                                 grc_local_ctrl &= ~GRC_LCLCTRL_GPIO_OUTPUT2;
-                                tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                                       grc_local_ctrl);
-                                udelay(100);
+                                tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                            grc_local_ctrl, 100);
                         }
                 }
         } else {
@@ -1094,19 +1105,16 @@ static void tg3_frob_aux_power(struct tg3 *tp)
                             (tp_peer->tg3_flags & TG3_FLAG_INIT_COMPLETE) != 0)
                                 return;
 
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                             (GRC_LCLCTRL_GPIO_OE1 |
-                              GRC_LCLCTRL_GPIO_OUTPUT1));
-                        udelay(100);
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                    (GRC_LCLCTRL_GPIO_OE1 |
+                                     GRC_LCLCTRL_GPIO_OUTPUT1), 100);
 
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                             (GRC_LCLCTRL_GPIO_OE1));
-                        udelay(100);
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                    GRC_LCLCTRL_GPIO_OE1, 100);
 
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
-                             (GRC_LCLCTRL_GPIO_OE1 |
-                              GRC_LCLCTRL_GPIO_OUTPUT1));
-                        udelay(100);
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl |
+                                    (GRC_LCLCTRL_GPIO_OE1 |
+                                     GRC_LCLCTRL_GPIO_OUTPUT1), 100);
                 }
         }
 }
@@ -1149,10 +1157,8 @@ static int tg3_set_power_state(struct tg3 *tp, int state)
                 udelay(100);    /* Delay after power state change */
 
                 /* Switch out of Vaux if it is not a LOM */
-                if (!(tp->tg3_flags & TG3_FLAG_EEPROM_WRITE_PROT)) {
-                        tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl);
-                        udelay(100);
-                }
+                if (!(tp->tg3_flags & TG3_FLAG_EEPROM_WRITE_PROT))
+                        tw32_wait_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl, 100);
 
                 return 0;
 
@@ -1251,10 +1257,8 @@ static int tg3_set_power_state(struct tg3 *tp, int state)
                 base_val |= (CLOCK_CTRL_RXCLK_DISABLE |
                              CLOCK_CTRL_TXCLK_DISABLE);
 
-                tw32_f(TG3PCI_CLOCK_CTRL, base_val |
-                     CLOCK_CTRL_ALTCLK |
-                     CLOCK_CTRL_PWRDOWN_PLL133);
-                udelay(40);
+                tw32_wait_f(TG3PCI_CLOCK_CTRL, base_val | CLOCK_CTRL_ALTCLK |
+                            CLOCK_CTRL_PWRDOWN_PLL133, 40);
         } else if (tp->tg3_flags2 & TG3_FLG2_5780_CLASS) {
                 /* do nothing */
         } else if (!((tp->tg3_flags2 & TG3_FLG2_5750_PLUS) &&
@@ -1275,11 +1279,11 @@ static int tg3_set_power_state(struct tg3 *tp, int state)
                         newbits2 = newbits1 | CLOCK_CTRL_44MHZ_CORE;
                 }
 
-                tw32_f(TG3PCI_CLOCK_CTRL, tp->pci_clock_ctrl | newbits1);
-                udelay(40);
+                tw32_wait_f(TG3PCI_CLOCK_CTRL, tp->pci_clock_ctrl | newbits1,
+                            40);
 
-                tw32_f(TG3PCI_CLOCK_CTRL, tp->pci_clock_ctrl | newbits2);
-                udelay(40);
+                tw32_wait_f(TG3PCI_CLOCK_CTRL, tp->pci_clock_ctrl | newbits2,
+                            40);
 
                 if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS)) {
                         u32 newbits3;
@@ -1293,9 +1297,8 @@ static int tg3_set_power_state(struct tg3 *tp, int state)
                                 newbits3 = CLOCK_CTRL_44MHZ_CORE;
                         }
 
-                        tw32_f(TG3PCI_CLOCK_CTRL,
-                                         tp->pci_clock_ctrl | newbits3);
-                        udelay(40);
+                        tw32_wait_f(TG3PCI_CLOCK_CTRL,
+                                    tp->pci_clock_ctrl | newbits3, 40);
                 }
         }