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Commit 0d978eb7 authored by Grygorii Strashko's avatar Grygorii Strashko Committed by Sekhar Nori
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gpio: davinci: use chained_irq_enter/chained_irq_exit API 



It's unsafe to call IRQ chip callbacks (.irq_mask/irq_unmask/irq_ack)
from chained IRQ handler directly. Because, Davinci GPIO block is used
by different SoCs, which, in turn, have different Main IRQ controllers
(Davinci - aintc, cp-intc; Keystone - arm-gic) which may introduce
diffrent set of IRQ chip callbacks. As result, call of
gpio_irq_handler() on Keysone will simply cause crash the system,
because ARM-GIC implements .irq_eoi() instead of .irq_ack().

Hence, fix it by using Kernel chained_irq_enter/chained_irq_exit APIs as
they are intended to handle exact such cases.

Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: default avatarSekhar Nori <nsekhar@ti.com>
parent c770844c

drivers/gpio/gpio-davinci.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/of_device.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/platform_device.h>

#include <linux/platform_data/gpio-davinci.h>

#include <linux/platform_data/gpio-davinci.h>

#include <linux/irqchip/chained_irq.h>





struct davinci_gpio_regs {

struct davinci_gpio_regs {

	u32	dir;

	u32	dir;
@@ -321,8 +322,7 @@ gpio_irq_handler(unsigned irq, struct irq_desc *desc) 
		mask <<= 16;

		mask <<= 16;





	/* temporarily mask (level sensitive) parent IRQ */

	/* temporarily mask (level sensitive) parent IRQ */

	desc->irq_data.chip->irq_mask(&desc->irq_data);

	chained_irq_enter(irq_desc_get_chip(desc), desc);

	desc->irq_data.chip->irq_ack(&desc->irq_data);

	while (1) {

	while (1) {

		u32		status;

		u32		status;

		int		bit;

		int		bit;
@@ -343,7 +343,7 @@ gpio_irq_handler(unsigned irq, struct irq_desc *desc) 
						 d->chip.base + bit));

						 d->chip.base + bit));

		}

		}

	}

	}

	desc->irq_data.chip->irq_unmask(&desc->irq_data);

	chained_irq_exit(irq_desc_get_chip(desc), desc);

	/* now it may re-trigger */

	/* now it may re-trigger */

}

}