Re: [PATCH] pinctrl/amd: poll InterruptEnable bits in amd_gpio_irq_set_type

From: Linus Walleij
Date: Tue Sep 25 2018 - 06:41:52 EST

On Sat, Sep 22, 2018 at 9:58 PM Daniel Kurtz <djkurtz@xxxxxxxxxxxx> wrote:

> From the AMD BKDG, if WAKE_INT_MASTER_REG.MaskStsEn is set, a software
> write to the debounce registers of *any* gpio will block wake/interrupt
> status generation for *all* gpios for a length of time that depends on
> WAKE_INT_MASTER_REG.MaskStsLength[11:0]. During this period the Interrupt
> Delivery bit (INTERRUPT_ENABLE) will read as 0.
> In commit 4c1de0414a1340 ("pinctrl/amd: poll InterruptEnable bits in
> enable_irq") we tried to fix this same "gpio Interrupts are blocked
> immediately after writing debounce registers" problem, but incorrectly
> assumed it only affected the gpio whose debounce was being configured
> and not ALL gpios.
> To solve this for all gpios, we move the polling loop from
> amd_gpio_irq_enable() to amd_gpio_irq_set_type(), while holding the gpio
> spinlock. This ensures that another gpio operation (e.g.
> amd_gpio_irq_unmask()) can read a temporarily disabled IRQ and
> incorrectly disable it while trying to modify some other register bits.
> Fixes: 4c1de0414a1340 pinctrl/amd: poll InterruptEnable bits in enable_irq
> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>

Patch applied for fixes.

Linus Walleij