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author | Johan Hovold <johan@kernel.org> | 2015-05-04 17:10:28 +0200 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2015-05-12 10:46:31 +0200 |
commit | 52176d0d3be29ccb01a44ee77532bb3969939ecf (patch) | |
tree | c9ba29e8f5031f40a50254b012a9c176c6d71a2b /drivers/gpio | |
parent | fab28b89a1c418382638d3837739faad9111fa8e (diff) | |
download | linux-52176d0d3be29ccb01a44ee77532bb3969939ecf.tar.gz linux-52176d0d3be29ccb01a44ee77532bb3969939ecf.tar.bz2 linux-52176d0d3be29ccb01a44ee77532bb3969939ecf.zip |
gpio: sysfs: fix redundant lock-as-irq handling
Drivers should call gpiochip_lock_as_irq (which prevents the pin
direction from being changed) in their irq_request_resources callbacks
but some drivers currently fail to do so.
Instead a second, explicit and often redundant call to lock-as-irq is
made by the sysfs-interface implementation after an irq has been
requested.
Move the explicit call before the irq-request to match the unlock done
after the irq is later released. Note that this also fixes an irq leak,
should the explicit call ever have failed.
Also add a comment about removing the redundant call once the broken
drivers have been fixed.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r-- | drivers/gpio/gpiolib-sysfs.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index af3bc7a8033b..b2b62cc6f9e1 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -195,20 +195,28 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, } } - ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, - "gpiolib", value_sd); + /* + * FIXME: This should be done in the irq_request_resources callback + * when the irq is requested, but a few drivers currently fail + * to do so. + * + * Remove this redundant call (along with the corresponding + * unlock) when those drivers have been fixed. + */ + ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc)); if (ret < 0) goto free_id; - ret = gpiochip_lock_as_irq(desc->chip, gpio_chip_hwgpio(desc)); - if (ret < 0) { - gpiod_warn(desc, "failed to flag the GPIO for IRQ\n"); - goto free_id; - } + ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, + "gpiolib", value_sd); + if (ret < 0) + goto err_unlock; desc->flags |= gpio_flags; return 0; +err_unlock: + gpiochip_unlock_as_irq(desc->chip, gpio_chip_hwgpio(desc)); free_id: idr_remove(&dirent_idr, id); desc->flags &= GPIO_FLAGS_MASK; |