Re: Reg. kernel crash while using pixcir touchscreen driver

Hi Dmitry,

Thank you for your reply.


On 24/05/2012, Dmitry Torokhov [off-list ref] wrote:

Hi Sachin,

On Thu, May 24, 2012 at 11:20:01AM +0530, Sachin Kamat wrote:

quoted

Hi,

I encountered a kernel crash while integrating Pixcir touchscreen
driver with one of our hardware. The log is attached at the end of the
mail (inline).

The following ISR code:

while (!tsdata->exiting) {
        pixcir_ts_poscheck(tsdata);

        if (tsdata->chip->attb_read_val())
              break;

        msleep(20);
}

seems to run until the if condition is false. However, when it exits
the loop (when the condition becomes true), it crashes saying "exiting
task "irq/438-pixcir_" (1011) is an active IRQ thread".

It actually crashes earlier, in pixcir_ts_isr() itself. The message is
coming from do_exit() when ISR thread dies. Did you porvide
attb_read_val implementation?

Yes, i did provide the implementation for it.
In fact even a simplest implementation where I return a positive
integer (for testing) results in the above crash.

quoted

I have 2 questions here:
1. Do we need such a loop and the if condition. In my case it worked
with the isr just doing
pixcir_ts_poscheck(tsdata);

2. What exactly is expected by attb_read_val() function.

I believe it is supposed to indicate if touch is detected so we can keep
polling.

Thanks.

--
Dmitry

-- 
With warm regards,
Sachin