[Letux-kernel] no interrupts from touchscreen

[Andreas Kemnade]

Hi,

On Wed, 22 Aug 2018 23:31:29 +0200
"H. Nikolaus Schaller" <hns at goldelico.com> wrote:

> Hi,
> 
> > Am 20.08.2018 um 20:05 schrieb Andreas Kemnade <andreas at kemnade.info>:
> > 
> > Hi,
> > 
> > at the moment I do not get interrupts from touchscreen.
> > I am working with 4.17. It seems to have stopped working after suspend.
> > This happens randomly, seen it with different kernels. At this time I have
> > a working usb connection and investigated.
> > via iio I could read out x/y and pressure. They seem to behave same.
> > Pressure can go up to > 1000
> > 
> > But I do not get interrupts.
> > Nothing happens in /proc/interrupts.  
> 
> strange. I have just tested with 4.18.4 on a GTA04A4:
> 
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2369  49058000.gpio   0 Edge      tsc2007
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2369  49058000.gpio   0 Edge      tsc2007
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2369  49058000.gpio   0 Edge      tsc2007
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2383  49058000.gpio   0 Edge      tsc2007
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2383  49058000.gpio   0 Edge      tsc2007
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2397  49058000.gpio   0 Edge      tsc2007
> root at letux:~# cat /proc/interrupts |fgrep tsc2007
> 168:       2408  49058000.gpio   0 Edge      tsc2007
> root at letux:~#
> 
Well, most of the time it works, I did not find a clear pattern
for this problem. It usually only happens when I am not in a situation
so that I can debug that or want to debug something else. 
Suspend seems to be involved.
I have seen it running the weather monitor for long times.

What puzzles me is that I can get the raw values using iio,
so i2c seems not to be stuck. 

[...]
> > 
> > 
> > This stays the same regards if I touch or not  
> 
> same for me
> 
> > root at gta04:~# devmem2 0x49058038 w
> > /dev/mem opened.
> > Memory mapped at address 0xb6f4b000.
> > Value at address 0x49058038 (0xb6f4b038): 0xB001  
> 
So GPIO_DATAIN does not change for you? 

> > root at gta04:~# devmem2 0x49058034 w
> > /dev/mem opened.
> > Memory mapped at address 0xb6f77000.
> > Value at address 0x49058034 (0xb6f77034): 0xFBFFBFFF  
> 
> root at letux:~# /usr/bin/arm-linux-gnueabihf/devmem2 devmem2 0x49058034 w
> /dev/mem opened.
> Memory mapped at address 0xb6fd6000.
> Illegal data type '0'.
> root at letux:~#
> 
devmem2 is duplicated in your commandline.

> > 
> > Any hints? reboot doen not help.
> > Power cycle helps.  
> 
> Maybe you can add some printk to tsc2007.c?
> 
Hmm, just sending
  /* Prepare for touch readings - power down ADC and enable PENIRQ */
        err = tsc2007_xfer(ts, PWRDOWN);

should be enough to get interrupts (or at least changing values in GPIO_DATAIN), shouldn't it? So in doubt an i2cset should be enough.
Just another strange thing: Why is TSC2007_SETUP never used?

Regards,
Andreas
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