Re: [PATCH v2 2/3] pinctrl: cherryview: Do not allow the same interrupt line to be used by 2 pins

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>]

On Thu, Nov 18, 2021 at 01:14:53PM +0200, Mika Westerberg wrote:
> On Thu, Nov 18, 2021 at 11:56:49AM +0100, Hans de Goede wrote:
> > It is impossible to use the same interrupt line for 2 pins, this will
> > result in the interrupts only being delivered to the IRQ handler for
> > the pin for which chv_gpio_irq_type() was called last.
> > 
> > The pinctrl-cherryview.c code relies on the BIOS to correctly setup the
> > interrupt line, but there is a BIOS bug on at least the Medion Akoya E1239T
> > and the GPD win models where both INT33FF:02 pin 8, used by the powerbutton
> > and INT33FF:02 pin 21 used as IRQ input for the accelerometer are mapped to
> > interrupt line 0.
> > 
> > This causes 2 problems:
> > 1. The accelerometer IRQ does not work, since the power button is probed
> > later taking over the intr_lines[0] slot.
> > 
> > 2. Since the accelerometer IRQ is not marked as wakeup, interrupt line 0
> > gets masked on suspend, causing the power button to not work to wake
> > the system from suspend.
> > 
> > Likewise on the Lenovo Yogabook, which has a touchscreen as keyboard
> > and the keyboard half of the tablet also has a Wacom digitizer, the BIOS
> > by default assigns the same interrupt line to the GPIOs used
> > for their interrupts.
> > 
> > Fix these problems by adding a check for this and assigning a new
> > interrupt line to the 2nd pin for which chv_gpio_irq_type() gets called.
> > 
> > With this fix in place the following 2 messages show up in dmesg on
> > the Medion Akoya E1239T and the GPD win:
> > 
> >  cherryview-pinctrl INT33FF:02: interrupt line 0 is used by both pin 21 and pin 8
> >  cherryview-pinctrl INT33FF:02: changing the interrupt line for pin 8 to 15
> > 
> > And the following gets logged on the Lenovo Yogabook:
> > 
> >  cherryview-pinctrl INT33FF:01: interrupt-line 0 is used by both pin 49 and pin 56
> >  cherryview-pinctrl INT33FF:01: changing the interrupt line for pin 56 to 7
> > 
> > Note commit 9747070c11d6 ("Input: axp20x-pek - always register interrupt
> > handlers") was added as a work around for the power button not being able
> > to wakeup the system. This relies on using the PMIC's connection to the
> > power button but that only works on systems with the AXP288 PMIC.
> > Once this fix has been merged that workaround can be removed.
> > 
> > Cc: Yauhen Kharuzhy <jekhor@xxxxxxxxx>
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> 
> Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

Pushed to my review and testing queue, thanks!

-- 
With Best Regards,
Andy Shevchenko