linux-kernel - Re: [PATCH] pinctrl: intel: Initialize GPIO properly when used through irqchip

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Message-ID: <20171129131109.GR22431@lahna.fi.intel.com>
Date:   Wed, 29 Nov 2017 15:11:09 +0200
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     Linus Walleij <linus.walleij@...aro.org>
Cc:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Daniel Drake <drake@...lessm.com>,
        Chris Chiu <chiu@...lessm.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-gpio@...r.kernel.org,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] pinctrl: intel: Initialize GPIO properly when used
 through irqchip

On Wed, Nov 29, 2017 at 01:39:00PM +0100, Linus Walleij wrote:
> On Mon, Nov 20, 2017 at 4:19 PM, Mika Westerberg
> <mika.westerberg@...ux.intel.com> wrote:
> 
> > When a GPIO is requested using gpiod_get_* APIs the intel pinctrl driver
> > switches the pin to GPIO mode and makes sure interrupts are routed to
> > the GPIO hardware instead of IOAPIC. However, if the GPIO is used
> > directly through irqchip, as is the case with many I2C-HID devices where
> > I2C core automatically configures interrupt for the device, the pin is
> > not initialized as GPIO. Instead we rely that the BIOS configures the
> > pin accordingly which seems not to be the case at least in Asus X540NA
> > SKU3 with Focaltech touchpad.
> >
> > When the pin is not properly configured it might result weird behaviour
> > like interrupts suddenly stop firing completely and the touchpad stops
> > responding to user input.
> >
> > Fix this by properly initializing the pin to GPIO mode also when it is
> > used directly through irqchip.
> >
> > Reported-by: Daniel Drake <drake@...lessm.com>
> > Reported-by: Chris Chiu <chiu@...lessm.com>
> > Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
> 
> Should this have a Fixes:?
> 
> Should this have a Cc: stable@...r.kernel.org?

Right, I'll add those in v2.

> > Chris, Daniel,
> >
> > Could you check that this still solves the issue and maybe provide your
> > Tested-by? Thanks!
> 
> Pls pick up Tested-by's when resending.

Sure.

> > +static void __intel_gpio_init_gpio(void __iomem *padcfg0)
> 
> I just don't like __underscore_means_inner_function() I
> strongly prefer function_has_a_proper_name() so please
> come up with something that describes what it is really doing
> and name it like that.
> 
> With that fixes, I'll apply it pronto.

No problem. I'll make v2 and send it out soon.