From 4585b000ace6438d0b142746baab658056b223d9 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 3 Aug 2015 12:46:38 +0300 Subject: [PATCH] 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: Mika Westerberg Signed-off-by: Linus Walleij --- drivers/pinctrl/intel/pinctrl-cherryview.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c index f9a4767..2984b46 100644 --- a/drivers/pinctrl/intel/pinctrl-cherryview.c +++ b/drivers/pinctrl/intel/pinctrl-cherryview.c @@ -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; -- 2.7.4