| Message ID | 1462350113-20216-1-git-send-email-geert+renesas@glider.be |
|---|---|
| State | New |
| Headers | show |
On Wed, May 4, 2016 at 10:21 AM, Geert Uytterhoeven <geert+renesas@glider.be> wrote: > Currrently the gpio_chip.to_irq() callback returns -ENOSYS on error, > which causes bad interactions with the serial_mctrl_gpio helpers. > > mctrl_gpio_init() returns -ENOSYS if GPIOLIB is not enabled, which is > intended to be ignored by its callers. However, ignoring -ENOSYS when it > was caused by a gpiod_to_irq() failure will lead to a crash later: > > Unable to handle kernel paging request at virtual address ffffffde > ... > PC is at mctrl_gpio_set+0x14/0x78 > > Fix this by returning zero instead, like gpiochip_to_irq() does. > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- > This depends on "gpio: make gpiod_to_irq() return negative for NO_IRQ" > for proper handling by callers of mctrl_gpio_init(). > Hence I think it's best to take this through the GPIO tree, after the > above has been applied. > > v2: > - Return zero instead of -ENXIO. Patch applied. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pinctrl/sh-pfc/gpio.c b/drivers/pinctrl/sh-pfc/gpio.c index a6681b8b17c3b30c..97dff6a09ff08115 100644 --- a/drivers/pinctrl/sh-pfc/gpio.c +++ b/drivers/pinctrl/sh-pfc/gpio.c @@ -212,7 +212,7 @@ static int gpio_pin_to_irq(struct gpio_chip *gc, unsigned offset) } } - return -ENOSYS; + return 0; found: return pfc->irqs[i];
Currrently the gpio_chip.to_irq() callback returns -ENOSYS on error, which causes bad interactions with the serial_mctrl_gpio helpers. mctrl_gpio_init() returns -ENOSYS if GPIOLIB is not enabled, which is intended to be ignored by its callers. However, ignoring -ENOSYS when it was caused by a gpiod_to_irq() failure will lead to a crash later: Unable to handle kernel paging request at virtual address ffffffde ... PC is at mctrl_gpio_set+0x14/0x78 Fix this by returning zero instead, like gpiochip_to_irq() does. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- This depends on "gpio: make gpiod_to_irq() return negative for NO_IRQ" for proper handling by callers of mctrl_gpio_init(). Hence I think it's best to take this through the GPIO tree, after the above has been applied. v2: - Return zero instead of -ENXIO. --- drivers/pinctrl/sh-pfc/gpio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)