RE: [PATCH] HID: intel-thc-hid: intel-quickspi: reset touch IC on system resume

[Xu, Even]

Hi, Danny,

Thanks for your patient to have some many tries.

According to above tests, it seems Surface Pro 10 does not only power off the TIC but also the THC for suspend.
Then your patch is need for this case.
I will add my review flag for your patch, thanks for your attribution!

Best Regards,
Even Xu

> -----Original Message-----
> From: d3z <d3z.the.dev@xxxxxxxxx>
> Sent: Friday, June 5, 2026 4:27 AM
> To: Xu, Even <even.xu@xxxxxxxxx>; Sun, Xinpeng <xinpeng.sun@xxxxxxxxx>;
> jikos@xxxxxxxxxx; bentiss@xxxxxxxxxx
> Cc: Danny D . <d3z.the.dev@xxxxxxxxx>; linux-input@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; abhishektamboli9@xxxxxxxxx;
> sakari.ailus@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] HID: intel-thc-hid: intel-quickspi: reset touch IC on system
> resume
> 
> From: Danny D. <d3z.the.dev@xxxxxxxxx>
> 
> Hi Even,
> 
> Good catch on the missing state restore. I rebuilt with your version and re-ran the
> test.
> 
> This is exactly your proposal: reset_tic() after thc_dma_configure(), then qsdev-
> >state = QUICKSPI_ENABLED, with no thc_spi_*_config and no thc_ltr_*. I built it
> as a module and swapped it into a clean linux-surface 6.19.8 on the Surface Pro
> 10.
> 
> It still doesn't survive s2idle - touch is fine at probe, but after one
> suspend/resume it's dead again. This time resume() fails outright instead of
> coming back quietly broken:
> 
>     intel_quickspi 0000:00:10.0: Wait DEVICE_DESCRIPTOR timeout, ret:0
>     intel_quickspi 0000:00:10.0: PM: dpm_run_callback(): pci_pm_resume returns
> -110
>     intel_quickspi 0000:00:10.0: PM: failed to resume async: error -110
> 
> So reset_tic() can't complete here. It clears the reset handshake, then times out
> in quickspi_get_device_descriptor() and the whole resume bails with -
> ETIMEDOUT. The device isn't a wake source on this box - "Can't find wake GPIO
> resource" - so device_may_wakeup() is false and we're on the reset path, as
> expected.
> 
> And the timeout is the THC, not the touch IC: across s2idle its SPI input/output
> address and read/write config are gone, so reset_tic()'s descriptor exchange has
> nothing valid to run against. Reprogram those first - the
> thc_spi_input_output_address_config + read_config + write_config block, same
> as quickspi_restore(), same as v2 on the no-wake path - and reset_tic() completes
> and touch comes back. That's exactly why
> v2 reconfigures the THC instead of only resetting the IC.
> 
> One more platform note: the SP10 never reaches S3. Firmware only offers s2idle -
> mem_sleep is just "[s2idle]", with no "deep" entry to select - yet the THC still
> loses its context across plain s2idle. So a reset gated on S3 would never fire here,
> which is why it has to run on the ordinary resume path.
> 
> Thanks,
> Danny