Hi Chris,
On Tue, Dec 17, 2013 at 12:16:01PM -0800, Christopher Heiny wrote:
> This patch fixes two bugs in handling of the RMI4 attention line GPIO.
>
> 1) in enable_sensor(), make sure the attn_gpio is defined before attempting to
> get its value.
>
> 2) in rmi_driver_probe(), declare the name of the attn_gpio, then
> request the attn_gpio before attempting to export it.
>
> Also introduces a GPIO_LABEL constant for identifying the attention GPIO.
>
I was looking at the patch some more and I have some concerns with it.
> Signed-off-by: Christopher Heiny <cheiny@xxxxxxxxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
>
> ---
>
> drivers/input/rmi4/rmi_driver.c | 28 +++++++++++++++++-----------
> 1 file changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
> index a30c7d3..33fb8f8 100644
> --- a/drivers/input/rmi4/rmi_driver.c
> +++ b/drivers/input/rmi4/rmi_driver.c
> @@ -169,7 +169,7 @@ static int enable_sensor(struct rmi_device *rmi_dev)
>
> data->enabled = true;
>
> - if (!pdata->level_triggered &&
> + if (pdata->attn_gpio && !pdata->level_triggered &&
O is perfectly fine GPIO number, you want to use gpio_is_valid() hete. I
also wonder why do you need such elaborate check. Can we simply "flush"
device before enabling interrupts?
> gpio_get_value(pdata->attn_gpio) == pdata->attn_polarity)
> retval = process_interrupt_requests(rmi_dev);
>
> @@ -807,6 +807,8 @@ static int rmi_driver_remove(struct device *dev)
> return 0;
> }
>
> +static const char GPIO_LABEL[] = "attn";
> +
> static int rmi_driver_probe(struct device *dev)
> {
> struct rmi_driver *rmi_driver;
> @@ -959,20 +961,24 @@ static int rmi_driver_probe(struct device *dev)
> }
>
> if (IS_ENABLED(CONFIG_RMI4_DEV) && pdata->attn_gpio) {
> - retval = gpio_export(pdata->attn_gpio, false);
> + retval = gpio_request(pdata->attn_gpio, GPIO_LABEL);
Here it is too late to request GPIO. You have been converting it to IRQ,
enabling that IRQ and calling gpio_get_value() so GPIO should have
already been requested by now.
So you need to move this code up. You may also consider using
gpio_request_one() and use GPIOF_EXPORT flag if you want to export it.
It would also be nice to set the direction (GPIOF_DIR_IN).
I also do not see matching call to gpio_free() in remove().
> if (retval) {
> - dev_warn(dev, "WARNING: Failed to export ATTN gpio!\n");
> - retval = 0;
> + dev_warn(dev, "WARNING: Failed to request ATTN gpio %d, code: %d.\n",
> + pdata->attn_gpio, retval);
> } else {
> - retval = gpio_export_link(dev,
> - "attn", pdata->attn_gpio);
> + retval = gpio_export(pdata->attn_gpio, false);
> if (retval) {
> - dev_warn(dev,
> - "WARNING: Failed to symlink ATTN gpio!\n");
> - retval = 0;
> + dev_warn(dev, "WARNING: Failed to export ATTN gpio %d, code: %d.\n",
> + pdata->attn_gpio, retval);
> } else {
> - dev_info(dev, "Exported ATTN GPIO %d.",
> - pdata->attn_gpio);
> + retval = gpio_export_link(dev, GPIO_LABEL,
> + pdata->attn_gpio);
> + if (retval)
> + dev_warn(dev,
> + "WARNING: Failed to symlink ATTN gpio!\n");
> + else
> + dev_info(dev, "Exported ATTN GPIO %d.",
> + pdata->attn_gpio);
> }
> }
> }
Thanks.
--
Dmitry
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