Hi Dmitry,
On Thu, Feb 03, 2011 at 08:54:05AM -0800, Dmitry Torokhov wrote:
>> On Thu, Feb 03, 2011 at 08:51:46PM +0530, Sourav Poddar wrote:
>>> The ads7846 driver requests a gpio but does not currently
>>> configure it explicitly as an input. Use gpio_request_one
>>> to request and configure it at one shot.
>>>
>>> Signed-off-by: Sourav Poddar <sourav.pod...@ti.com>
>>> Cc: Dmitry Torokhov <d...@mail.ru>
>> Will apply this one, the other one is a bit messy IMO, will have to
>> think about it.
>>
> Something like below should do I think.
Personally, I don't like the "if{}else if{}else{}" stuff and prefer spartan
programming techniques instead, but the "if-else" below still looks ok,
having a single success exit point is important and everybody is fine
with that approach - then I'm fine with it too.
Thanks for hopping in :)
>
> Dmitry
>
>
> Input: ads7846 - check proper condition when freeing gpio
>
> From: Dmitry Torokhov <dmitry.torok...@gmail.com>
>
> When driver uses custom pendown detection method gpio_pendown is not
> set up and so we should not try to free it, otherwise we are presented
> with:
>
> ------------[ cut here ]------------
> WARNING: at drivers/gpio/gpiolib.c:1258 gpio_free+0x100/0x12c()
> Modules linked in:
> [<c0061208>] (unwind_backtrace+0x0/0xe4) from
> [<c0091f58>](warn_slowpath_common+0x4c/0x64)
> [<c0091f58>] (warn_slowpath_common+0x4c/0x64) from
> [<c0091f88>](warn_slowpath_null+0x18/0x1c)
> [<c0091f88>] (warn_slowpath_null+0x18/0x1c) from
> [<c024e610>](gpio_free+0x100/0x12c)
> [<c024e610>] (gpio_free+0x100/0x12c) from
> [<c03e9fbc>](ads7846_probe+0xa38/0xc5c)
> [<c03e9fbc>] (ads7846_probe+0xa38/0xc5c) from
> [<c02cff14>](spi_drv_probe+0x18/0x1c)
> [<c02cff14>] (spi_drv_probe+0x18/0x1c) from
> [<c028bca4>](driver_probe_device+0xc8/0x184)
> [<c028bca4>] (driver_probe_device+0xc8/0x184) from
> [<c028bdc8>](__driver_attach+0x68/0x8c)
> [<c028bdc8>] (__driver_attach+0x68/0x8c) from
> [<c028b4c8>](bus_for_each_dev+0x48/0x74)
> [<c028b4c8>] (bus_for_each_dev+0x48/0x74) from
> [<c028ae08>](bus_add_driver+0xa0/0x220)
> [<c028ae08>] (bus_add_driver+0xa0/0x220) from
> [<c028c0c0>](driver_register+0xa8/0x134)
> [<c028c0c0>] (driver_register+0xa8/0x134) from
> [<c0050550>](do_one_initcall+0xcc/0x1a4)
> [<c0050550>] (do_one_initcall+0xcc/0x1a4) from
> [<c00084e4>](kernel_init+0x14c/0x214)
> [<c00084e4>] (kernel_init+0x14c/0x214) from
> [<c005b494>](kernel_thread_exit+0x0/0x8)
> ---[ end trace 4053287f8a5ec18f ]---
>
> Also rearrange ads7846_setup_pendown() to have only one exit point
> returning success.
>
> Reported-by: Sourav Poddar <sourav.pod...@ti.com>
> Signed-off-by: Dmitry Torokhov <d...@mail.ru>
> ---
>
> drivers/input/touchscreen/ads7846.c | 39
> ++++++++++++++++++++---------------
> 1 files changed, 22 insertions(+), 17 deletions(-)
>
>
> diff --git a/drivers/input/touchscreen/ads7846.c
> b/drivers/input/touchscreen/ads7846.c
> index 0e9492d..b1217e1 100644
> --- a/drivers/input/touchscreen/ads7846.c
> +++ b/drivers/input/touchscreen/ads7846.c
> @@ -946,30 +946,30 @@ static int __devinit ads7846_setup_pendown(struct
> spi_device *spi, struct ads784
> struct ads7846_platform_data *pdata = spi->dev.platform_data;
> int err;
>
> - /* REVISIT when the irq can be triggered active-low, or if for some
> + /*
> + * REVISIT when the irq can be triggered active-low, or if for some
> * reason the touchscreen isn't hooked up, we don't need to access
> * the pendown state.
> */
> - if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {
> - dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
> - return -EINVAL;
> - }
>
> if (pdata->get_pendown_state) {
> ts->get_pendown_state = pdata->get_pendown_state;
> - return 0;
> - }
> + } else if (gpio_is_valid(pdata->gpio_pendown)) {
> +
> + err = gpio_request_one(pdata->gpio_pendown, GPIOF_DIR_IN,
> + "ads7846_pendown");
> + if (err) {
> + dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
> + pdata->gpio_pendown);
> + return err;
> + }
>
> - err = gpio_request_one(pdata->gpio_pendown, GPIOF_DIR_IN,
> - "ads7846_pendown");
> - if (err) {
> - dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
> - pdata->gpio_pendown);
> - return err;
> + ts->gpio_pendown = pdata->gpio_pendown;
> + } else {
> + dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
> + return -EINVAL;
> }
>
> - ts->gpio_pendown = pdata->gpio_pendown;
> -
> return 0;
> }
>
> @@ -1359,7 +1359,7 @@ static int __devinit ads7846_probe(struct spi_device
> *spi)
> err_put_regulator:
> regulator_put(ts->reg);
> err_free_gpio:
> - if (ts->gpio_pendown != -1)
> + if (!ts->get_pendown_state)
> gpio_free(ts->gpio_pendown);
> err_cleanup_filter:
> if (ts->filter_cleanup)
> @@ -1389,8 +1389,13 @@ static int __devexit ads7846_remove(struct spi_device
> *spi)
> regulator_disable(ts->reg);
> regulator_put(ts->reg);
>
> - if (ts->gpio_pendown != -1)
> + if (!ts->get_pendown_state) {
> + /*
> + * If we are not using specialized pendown method we must
> + * have been relying on gpio we set up ourselves.
> + */
> gpio_free(ts->gpio_pendown);
> + }
>
> if (ts->filter_cleanup)
> ts->filter_cleanup(ts->filter_data);
>
>
>
--
Regards,
Igor.
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