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>
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index af3bc7a..b2b62cc 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -195,20 +195,28 @@
}
}
- 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;