-----Original Message-----
From: Bastien Nocera [mailto:hadess@hadess.net]
Sent: 29 September, 2015 5:04
To: Tirdea, Irina; linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org; Rob Herring; Pawel Moll; Ian Campbell; Kumar Gala; Purdila, Octavian; Dmitry Torokhov; Mark
Rutland; devicetree@vger.kernel.org
Subject: Re: [PATCH v3 1/5] Input: goodix - reset device at init

On Fri, 2015-09-25 at 21:04 +0000, Tirdea, Irina wrote:

quoted

<snip>

quoted

The warning from your dmesg output will not cause probe to fail.
If you look at the code for byt_gpio_direction_output, it will just
print
a warning and continue [1]:
	WARN(readl(conf_reg) & BYT_DIRECT_IRQ_EN,
		"Potential Error: Setting GPIO with direct_irq_en to
output");
I thought probe finishes successfully, but due to the warning in
dmesg you
are not sure whether the IRQ GPIO pin can be used as output.
If probe fails, it must be for another reason than the direct_irq_en
warning.

quoted

Would you have a patch for me to test that would bypass this error,
or
at least fallback gracefully to not resetting, not probing GPIOs if
they're badly setup?

If the driver fails to initialize the GPIOs, it will at least print
some
"Failed to get GPIO" warnings in dmesg. Do you have such messages in
dmesg or any additional information on why probe fails?

The current code will ignore GPIOs if they are not defined in ACPI
(see the check for -ENOENT), but does not ignore other error codes.
If you want to bypass all GPIO errors, you can use the code below.

The failure isn't there, it's when running goodix_i2c_test():
Sep 25 16:39:20 winbook kernel: Goodix-TS i2c-GDIX1001:00: i2c test failed attempt 1: -121
Sep 25 16:39:20 winbook kernel: Goodix-TS i2c-GDIX1001:00: i2c test failed attempt 2: -121
Sep 25 16:39:20 winbook kernel: Goodix-TS i2c-GDIX1001:00: I2C communication failure: -121
Sep 25 16:39:20 winbook kernel: Goodix-TS: probe of i2c-GDIX1001:00 failed with error -121

Are you using v6 of the patches? There was an issue with reset that Aleksei reported
and was fixed in v6 (although he had a different i2c error and a different scenario).

The GPIO setup seems to work (bar the warnings), and the reset as well,
but then the device fails to communicate. Likely a fallout from the
reset actually failing.

Swapping around the RST and INT pins leads to the same problem. Either
this device's GPIO PINs aren't actually functional, and the firmware
contains garbage, or something else is wrong.

I agree. Either the interrupt pin cannot be used as output in your configuration
or there are some specifics in the ACPI tables that prevent using these pins. 

I'm not sure how we can detect, and blacklist, those devices. At least
my original device, the Onda v975w, and the WinBook TW100 would have
those problems.

I can use DMI quirks to exclude these devices from using the features that
depend on the gpio pins. I already have the DMI information for WinBook TW100
and WinBook TW700. Could you tell me the DMI_SYS_VENDOR and
DMI_PRODUCT_NAME for Onda v975w so I can add it as well?

Thanks,
Irina

Cheers