Commit e12963c4 authored Jan 19, 2022 by Andy Shevchenko

pinctrl: intel: Fix a glitch when updating IRQ flags on a preconfigured line



The commit af7e3eeb ("pinctrl: intel: Disable input and output buffer
when switching to GPIO") hadn't taken into account an update of the IRQ
flags scenario.

When updating the IRQ flags on the preconfigured line the ->irq_set_type()
is called again. In such case the sequential Rx buffer configuration
changes may trigger a falling or rising edge interrupt that may lead,
on some platforms, to an undesired event.

This may happen because each of intel_gpio_set_gpio_mode() and
__intel_gpio_set_direction() updates the pad configuration with a different
value of the GPIORXDIS bit. Notable, that the intel_gpio_set_gpio_mode() is
called only for the pads that are configured as an input. Due to this fact,
integrate the logic of __intel_gpio_set_direction() call into the
intel_gpio_set_gpio_mode() so that the Rx buffer won't be disabled and
immediately re-enabled.

Fixes: af7e3eeb ("pinctrl: intel: Disable input and output buffer when switching to GPIO")
Reported-by: Kane Chen <kane.chen@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Grace Kao <grace.kao@intel.com>

parent e986f0e6

drivers/pinctrl/intel/pinctrl-intel.c

+2 −8

Original line number	Diff line number	Diff line
		@@ -451,8 +451,8 @@ static void intel_gpio_set_gpio_mode(void __iomem *padcfg0)
		value &= ~PADCFG0_PMODE_MASK;
		value \|= PADCFG0_PMODE_GPIO;

		/* Disable input and output buffers */
		value \|= PADCFG0_GPIORXDIS;
		/* Disable TX buffer and enable RX (this will be input) */
		value &= ~PADCFG0_GPIORXDIS;
		value \|= PADCFG0_GPIOTXDIS;

		/* Disable SCI/SMI/NMI generation */
		@@ -497,9 +497,6 @@ static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,

		intel_gpio_set_gpio_mode(padcfg0);

		/* Disable TX buffer and enable RX (this will be input) */
		__intel_gpio_set_direction(padcfg0, true);

		raw_spin_unlock_irqrestore(&pctrl->lock, flags);

		return 0;
		@@ -1115,9 +1112,6 @@ static int intel_gpio_irq_type(struct irq_data *d, unsigned int type)

		intel_gpio_set_gpio_mode(reg);

		/* Disable TX buffer and enable RX (this will be input) */
		__intel_gpio_set_direction(reg, true);

		value = readl(reg);

		value &= ~(PADCFG0_RXEVCFG_MASK \| PADCFG0_RXINV);