pinctrl: intel: Actually disable Tx and Rx buffers on GPIO request

Mistakenly the buffers (input and output) become enabled together for a short
period of time during GPIO request. This is problematic, because instead of
initial motive to disable them in the commit af7e3eeb
("pinctrl: intel: Disable input and output buffer when switching to GPIO"),
the driven value on the pin, which might be used as an IRQ line, brings
firmwares of some touch pads to an awkward state that needs a full power off
to recover. Fix this, as stated in the culprit commit, by disabling the buffers.

Fixes: af7e3eeb ("pinctrl: intel: Disable input and output buffer when switching to GPIO")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=210497


Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20201208182403.40435-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/intel/pinctrl-intel.c

@@ -442,8 +442,8 @@ static void intel_gpio_set_gpio_mode(void __iomem *padcfg0)
 	value |= PADCFG0_PMODE_GPIO;
 
 	/* Disable input and output buffers */
-	value &= ~PADCFG0_GPIORXDIS;
-	value &= ~PADCFG0_GPIOTXDIS;
+	value |= PADCFG0_GPIORXDIS;
+	value |= PADCFG0_GPIOTXDIS;
 
 	/* Disable SCI/SMI/NMI generation */
 	value &= ~(PADCFG0_GPIROUTIOXAPIC | PADCFG0_GPIROUTSCI);