[PATCHv2 1/2] ads7846: OMAP3: Removal of warnings backtrace in bootup

Sourav Poddar
2011-02-03T09:48:45Z

gpio_pendown in ads7846_probe is not getting initalized (defaulted to 0)
resulting in gpio_free to be called without a gpio_request. This
results in the following backtrace in bootup.

------------[ 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 ]---

Initializing gpio_pendown in ads7846_probe to -1 before
ads7846_setup_pendown function removes the above backtrace
warning.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/input/touchscreen/ads7846.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 14ea54b..036f245 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -1221,6 +1221,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
ts->input = input_dev;
ts->vref_mv = pdata->vref_mv;
ts->swap_xy = pdata->swap_xy;
+ ts->gpio_pendown = -1;

mutex_init(&ts->lock);
init_waitqueue_head(&ts->wait);
--
1.7.0.4