diff --git a/drivers/infiniband/hw/ipath/ipath_eeprom.c b/drivers/infiniband/hw/ipath/ipath_eeprom.c
index 030185f90ee..26daac9d8b6 100644
--- a/drivers/infiniband/hw/ipath/ipath_eeprom.c
+++ b/drivers/infiniband/hw/ipath/ipath_eeprom.c
@@ -95,39 +95,37 @@ static int i2c_gpio_set(struct ipath_devdata *dd,
 			enum i2c_type line,
 			enum i2c_state new_line_state)
 {
-	u64 read_val, write_val, mask, *gpioval;
+	u64 out_mask, dir_mask, *gpioval;
+	unsigned long flags = 0;
 
 	gpioval = &dd->ipath_gpio_out;
-	read_val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_extctrl);
-	if (line == i2c_line_scl)
-		mask = dd->ipath_gpio_scl;
-	else
-		mask = dd->ipath_gpio_sda;
-
-	if (new_line_state == i2c_line_high)
-		/* tri-state the output rather than force high */
-		write_val = read_val & ~mask;
-	else
-		/* config line to be an output */
-		write_val = read_val | mask;
-	ipath_write_kreg(dd, dd->ipath_kregs->kr_extctrl, write_val);
-
-	/* set high and verify */
-	if (new_line_state == i2c_line_high)
-		write_val = 0x1UL;
-	else
-		write_val = 0x0UL;
 
 	if (line == i2c_line_scl) {
-		write_val <<= dd->ipath_gpio_scl_num;
-		*gpioval = *gpioval & ~(1UL << dd->ipath_gpio_scl_num);
-		*gpioval |= write_val;
+		dir_mask = dd->ipath_gpio_scl;
+		out_mask = (1UL << dd->ipath_gpio_scl_num);
 	} else {
-		write_val <<= dd->ipath_gpio_sda_num;
-		*gpioval = *gpioval & ~(1UL << dd->ipath_gpio_sda_num);
-		*gpioval |= write_val;
+		dir_mask = dd->ipath_gpio_sda;
+		out_mask = (1UL << dd->ipath_gpio_sda_num);
 	}
+
+	spin_lock_irqsave(&dd->ipath_gpio_lock, flags);
+	if (new_line_state == i2c_line_high) {
+		/* tri-state the output rather than force high */
+		dd->ipath_extctrl &= ~dir_mask;
+	} else {
+		/* config line to be an output */
+		dd->ipath_extctrl |= dir_mask;
+	}
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_extctrl, dd->ipath_extctrl);
+
+	/* set output as well (no real verify) */
+	if (new_line_state == i2c_line_high)
+		*gpioval |= out_mask;
+	else
+		*gpioval &= ~out_mask;
+
 	ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_out, *gpioval);
+	spin_unlock_irqrestore(&dd->ipath_gpio_lock, flags);
 
 	return 0;
 }
@@ -145,8 +143,9 @@ static int i2c_gpio_get(struct ipath_devdata *dd,
 			enum i2c_type line,
 			enum i2c_state *curr_statep)
 {
-	u64 read_val, write_val, mask;
+	u64 read_val, mask;
 	int ret;
+	unsigned long flags = 0;
 
 	/* check args */
 	if (curr_statep == NULL) {
@@ -154,15 +153,21 @@ static int i2c_gpio_get(struct ipath_devdata *dd,
 		goto bail;
 	}
 
-	read_val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_extctrl);
 	/* config line to be an input */
 	if (line == i2c_line_scl)
 		mask = dd->ipath_gpio_scl;
 	else
 		mask = dd->ipath_gpio_sda;
-	write_val = read_val & ~mask;
-	ipath_write_kreg(dd, dd->ipath_kregs->kr_extctrl, write_val);
+
+	spin_lock_irqsave(&dd->ipath_gpio_lock, flags);
+	dd->ipath_extctrl &= ~mask;
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_extctrl, dd->ipath_extctrl);
+	/*
+	 * Below is very unlikely to reflect true input state if Output
+	 * Enable actually changed.
+	 */
 	read_val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_extstatus);
+	spin_unlock_irqrestore(&dd->ipath_gpio_lock, flags);
 
 	if (read_val & mask)
 		*curr_statep = i2c_line_high;
@@ -192,6 +197,7 @@ static void i2c_wait_for_writes(struct ipath_devdata *dd)
 
 static void scl_out(struct ipath_devdata *dd, u8 bit)
 {
+	udelay(1);
 	i2c_gpio_set(dd, i2c_line_scl, bit ? i2c_line_high : i2c_line_low);
 
 	i2c_wait_for_writes(dd);
@@ -314,12 +320,18 @@ static int eeprom_reset(struct ipath_devdata *dd)
 	int clock_cycles_left = 9;
 	u64 *gpioval = &dd->ipath_gpio_out;
 	int ret;
+	unsigned long flags;
 
-	eeprom_init = 1;
+	spin_lock_irqsave(&dd->ipath_gpio_lock, flags);
+	/* Make sure shadows are consistent */
+	dd->ipath_extctrl = ipath_read_kreg64(dd, dd->ipath_kregs->kr_extctrl);
 	*gpioval = ipath_read_kreg64(dd, dd->ipath_kregs->kr_gpio_out);
+	spin_unlock_irqrestore(&dd->ipath_gpio_lock, flags);
+
 	ipath_cdbg(VERBOSE, "Resetting i2c eeprom; initial gpioout reg "
 		   "is %llx\n", (unsigned long long) *gpioval);
 
+	eeprom_init = 1;
 	/*
 	 * This is to get the i2c into a known state, by first going low,
 	 * then tristate sda (and then tristate scl as first thing
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6110.c b/drivers/infiniband/hw/ipath/ipath_iba6110.c
index 4372c6c50ff..8482ea366fb 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6110.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6110.c
@@ -1059,6 +1059,7 @@ static void ipath_setup_ht_setextled(struct ipath_devdata *dd,
 				     u64 lst, u64 ltst)
 {
 	u64 extctl;
+	unsigned long flags = 0;
 
 	/* the diags use the LED to indicate diag info, so we leave
 	 * the external LED alone when the diags are running */
@@ -1075,6 +1076,7 @@ static void ipath_setup_ht_setextled(struct ipath_devdata *dd,
 			: INFINIPATH_IBCS_L_STATE_DOWN;
 	}
 
+	spin_lock_irqsave(&dd->ipath_gpio_lock, flags);
 	/*
 	 * start by setting both LED control bits to off, then turn
 	 * on the appropriate bit(s).
@@ -1103,6 +1105,7 @@ static void ipath_setup_ht_setextled(struct ipath_devdata *dd,
 	}
 	dd->ipath_extctrl = extctl;
 	ipath_write_kreg(dd, dd->ipath_kregs->kr_extctrl, extctl);
+	spin_unlock_irqrestore(&dd->ipath_gpio_lock, flags);
 }
 
 static void ipath_init_ht_variables(struct ipath_devdata *dd)
diff --git a/drivers/infiniband/hw/ipath/ipath_iba6120.c b/drivers/infiniband/hw/ipath/ipath_iba6120.c
index bcb70d67dbb..2345bb011ac 100644
--- a/drivers/infiniband/hw/ipath/ipath_iba6120.c
+++ b/drivers/infiniband/hw/ipath/ipath_iba6120.c
@@ -791,6 +791,7 @@ static void ipath_setup_pe_setextled(struct ipath_devdata *dd, u64 lst,
 				     u64 ltst)
 {
 	u64 extctl;
+	unsigned long flags = 0;
 
 	/* the diags use the LED to indicate diag info, so we leave
 	 * the external LED alone when the diags are running */
@@ -807,6 +808,7 @@ static void ipath_setup_pe_setextled(struct ipath_devdata *dd, u64 lst,
 			: INFINIPATH_IBCS_L_STATE_DOWN;
 	}
 
+	spin_lock_irqsave(&dd->ipath_gpio_lock, flags);
 	extctl = dd->ipath_extctrl & ~(INFINIPATH_EXTC_LED1PRIPORT_ON |
 				       INFINIPATH_EXTC_LED2PRIPORT_ON);
 
@@ -816,6 +818,7 @@ static void ipath_setup_pe_setextled(struct ipath_devdata *dd, u64 lst,
 		extctl |= INFINIPATH_EXTC_LED1PRIPORT_ON;
 	dd->ipath_extctrl = extctl;
 	ipath_write_kreg(dd, dd->ipath_kregs->kr_extctrl, extctl);
+	spin_unlock_irqrestore(&dd->ipath_gpio_lock, flags);
 }
 
 /**
diff --git a/drivers/infiniband/hw/ipath/ipath_init_chip.c b/drivers/infiniband/hw/ipath/ipath_init_chip.c
index 7045ba68949..f6ee7a83595 100644
--- a/drivers/infiniband/hw/ipath/ipath_init_chip.c
+++ b/drivers/infiniband/hw/ipath/ipath_init_chip.c
@@ -340,6 +340,8 @@ static int init_chip_first(struct ipath_devdata *dd,
 
 	spin_lock_init(&dd->ipath_tid_lock);
 
+	spin_lock_init(&dd->ipath_gpio_lock);
+
 done:
 	*pdp = pd;
 	return ret;
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index 2f39db7df31..bd1088a9989 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -399,6 +399,8 @@ struct ipath_devdata {
 	u64 ipath_gpio_out;
 	/* shadow the gpio mask register */
 	u64 ipath_gpio_mask;
+	/* shadow the gpio output enable, etc... */
+	u64 ipath_extctrl;
 	/* kr_revision shadow */
 	u64 ipath_revision;
 	/*
@@ -473,8 +475,6 @@ struct ipath_devdata {
 	u32 ipath_cregbase;
 	/* shadow the control register contents */
 	u32 ipath_control;
-	/* shadow the gpio output contents */
-	u32 ipath_extctrl;
 	/* PCI revision register (HTC rev on FPGA) */
 	u32 ipath_pcirev;
 
@@ -576,6 +576,9 @@ struct ipath_devdata {
 	u64 ipath_gpio_sda;
 	u64 ipath_gpio_scl;
 
+	/* lock for doing RMW of shadows/regs for ExtCtrl and GPIO */
+	spinlock_t ipath_gpio_lock;
+
 	/* used to override LED behavior */
 	u8 ipath_led_override;  /* Substituted for normal value, if non-zero */
 	u16 ipath_led_override_timeoff; /* delta to next timer event */