Re: [PATCH] Input: gpio_keys_polled - defer probing if GPIO probing is deferred
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2012-12-23 10:06:25
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
On Sun, Dec 23, 2012 at 09:32:03AM +0100, Gabor Juhos wrote:
quoted hunk ↗ jump to hunk
If GPIO probing is deferred, the driver tries to claim an invalid GPIO line which leads to an error message like this: gpio-keys-polled buttons.2: unable to claim gpio 4294966779, err=-22 gpio-keys-polled: probe of buttons.2 failed with error -22 The patch ensures that 'gpio_keys_polled_get_devtree_pdata' returns -EPROBE_DEFER if any of the GPIOs to register are deferred. Cc: <redacted> Signed-off-by: Gabor Juhos <redacted> --- drivers/input/keyboard/gpio_keys_polled.c | 6 ++++++ 1 file changed, 6 insertions(+)diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c index f686fd9..cfb54cc 100644 --- a/drivers/input/keyboard/gpio_keys_polled.c +++ b/drivers/input/keyboard/gpio_keys_polled.c@@ -120,6 +120,12 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct if (nbuttons == 0) return NULL; + for_each_child_of_node(node, pp) { + error = of_get_gpio(pp, 0); + if (error == -EPROBE_DEFER) + goto err_out; + } + pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button), GFP_KERNEL); if (!pdata) {--
Well spotted, thanks. However I think the patch should look like the one below as we should propagate all errors, not only -EPROBE_DEFER, up the stack. Thanks. -- Dmitry Input: gpio_keys_polled - defer probing if GPIO probing is deferred From: Gabor Juhos <redacted> If GPIO probing is deferred, the driver tries to claim an invalid GPIO line which leads to an error message like this: gpio-keys-polled buttons.2: unable to claim gpio 4294966779, err=-22 gpio-keys-polled: probe of buttons.2 failed with error -22 The patch ensures that error code returned by of_get_gpio_flags (including -EPROBE_DEFER) is propagated up the stack. Cc: stable@vger.kernel.org Signed-off-by: Gabor Juhos <redacted> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- drivers/input/keyboard/gpio_keys_polled.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index f686fd9..e75ca6b 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c@@ -135,6 +135,7 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct i = 0; for_each_child_of_node(node, pp) { + int gpio; enum of_gpio_flags flags; if (!of_find_property(pp, "gpios", NULL)) {
@@ -143,9 +144,19 @@ static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct continue; } + gpio = of_get_gpio_flags(pp, 0, &flags); + if (gpio < 0) { + error = gpio; + if (error != -EPROBE_DEFER) + dev_err(dev, + "Failed to get gpio flags, error: %d\n", + error); + goto err_free_pdata; + } + button = &pdata->buttons[i++]; - button->gpio = of_get_gpio_flags(pp, 0, &flags); + button->gpio = gpio; button->active_low = flags & OF_GPIO_ACTIVE_LOW; if (of_property_read_u32(pp, "linux,code", &button->code)) {