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Commit 4585b000 authored by Mika Westerberg's avatar Mika Westerberg Committed by Linus Walleij
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pinctrl: cherryview: Serialize all register access 



There is a hardware issue in Intel Braswell/Cherryview where concurrent
GPIO register access might results reads of 0xffffffff and writes might get
dropped.

Prevent this from happening by taking the serializing lock for all places
where it is possible that more than one thread might be accessing the
hardware concurrently.

Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 39b87ad1

drivers/pinctrl/intel/pinctrl-cherryview.c

+7 −1
Original line number Diff line number Diff line
@@ -1169,9 +1169,12 @@ static int chv_gpio_get(struct gpio_chip *chip, unsigned offset) 
{

	struct chv_pinctrl *pctrl = gpiochip_to_pinctrl(chip);

	int pin = chv_gpio_offset_to_pin(pctrl, offset);

	unsigned long flags;

	u32 ctrl0, cfg;



	spin_lock_irqsave(&pctrl->lock, flags);

	ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0));

	spin_unlock_irqrestore(&pctrl->lock, flags);



	cfg = ctrl0 & CHV_PADCTRL0_GPIOCFG_MASK;

	cfg >>= CHV_PADCTRL0_GPIOCFG_SHIFT;
@@ -1209,8 +1212,11 @@ static int chv_gpio_get_direction(struct gpio_chip *chip, unsigned offset) 
	struct chv_pinctrl *pctrl = gpiochip_to_pinctrl(chip);

	unsigned pin = chv_gpio_offset_to_pin(pctrl, offset);

	u32 ctrl0, direction;

	unsigned long flags;



	spin_lock_irqsave(&pctrl->lock, flags);

	ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0));

	spin_unlock_irqrestore(&pctrl->lock, flags);



	direction = ctrl0 & CHV_PADCTRL0_GPIOCFG_MASK;

	direction >>= CHV_PADCTRL0_GPIOCFG_SHIFT;
@@ -1313,6 +1319,7 @@ static unsigned chv_gpio_irq_startup(struct irq_data *d) 
		unsigned long flags;

		u32 intsel, value;



		spin_lock_irqsave(&pctrl->lock, flags);

		intsel = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0));

		intsel &= CHV_PADCTRL0_INTSEL_MASK;

		intsel >>= CHV_PADCTRL0_INTSEL_SHIFT;
@@ -1323,7 +1330,6 @@ static unsigned chv_gpio_irq_startup(struct irq_data *d) 
		else

			handler = handle_edge_irq;



		spin_lock_irqsave(&pctrl->lock, flags);

		if (!pctrl->intr_lines[intsel]) {

			irq_set_handler_locked(d, handler);

			pctrl->intr_lines[intsel] = offset;