From 0fbc9fdb7e747500111dcc4a5f5f3ceed0360d71 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Fri, 4 Feb 2011 00:37:26 -0800 Subject: [PATCH] Input: ads7846 - check proper condition when freeing gpio 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: [] (unwind_backtrace+0x0/0xe4) from [](warn_slowpath_common+0x4c/0x64) [] (warn_slowpath_common+0x4c/0x64) from [](warn_slowpath_null+0x18/0x1c) [] (warn_slowpath_null+0x18/0x1c) from [](gpio_free+0x100/0x12c) [] (gpio_free+0x100/0x12c) from [](ads7846_probe+0xa38/0xc5c) [] (ads7846_probe+0xa38/0xc5c) from [](spi_drv_probe+0x18/0x1c) [] (spi_drv_probe+0x18/0x1c) from [](driver_probe_device+0xc8/0x184) [] (driver_probe_device+0xc8/0x184) from [](__driver_attach+0x68/0x8c) [] (__driver_attach+0x68/0x8c) from [](bus_for_each_dev+0x48/0x74) [] (bus_for_each_dev+0x48/0x74) from [](bus_add_driver+0xa0/0x220) [] (bus_add_driver+0xa0/0x220) from [](driver_register+0xa8/0x134) [] (driver_register+0xa8/0x134) from [](do_one_initcall+0xcc/0x1a4) [] (do_one_initcall+0xcc/0x1a4) from [](kernel_init+0x14c/0x214) [] (kernel_init+0x14c/0x214) from [](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 Acked-by: Wolfram Sang Reviewed-by: Charulatha V Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/ads7846.c | 38 +++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 14ea54b..4bf2316 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -941,28 +941,29 @@ 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(pdata->gpio_pendown, "ads7846_pendown"); - if (err) { - dev_err(&spi->dev, "failed to request pendown GPIO%d\n", - pdata->gpio_pendown); - return err; - } + err = gpio_request(pdata->gpio_pendown, "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; + ts->gpio_pendown = pdata->gpio_pendown; + + } else { + dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); + return -EINVAL; + } return 0; } @@ -1353,7 +1354,7 @@ 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) @@ -1383,8 +1384,13 @@ 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); -- 2.7.4