RE: [PATCH v2 1/1] gpio: mlxbf3: Support shutdown() function

[Asmaa Mnebhi <asmaa@xxxxxxxxxx>]

Thank you Andy and Linus for approving my patch! 

Hi Bart, could you please apply this patch?

Thank you,
Asmaa

> -----Original Message-----
> From: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Sent: Monday, June 17, 2024 5:05 AM
> To: Asmaa Mnebhi <asmaa@xxxxxxxxxx>
> Cc: andy.shevchenko@xxxxxxxxx; bgolaszewski@xxxxxxxxxxxx; linux-
> gpio@xxxxxxxxxxxxxxx; David Thompson <davthompson@xxxxxxxxxx>
> Subject: Re: [PATCH v2 1/1] gpio: mlxbf3: Support shutdown() function
> Importance: High
> 
> On Tue, Jun 11, 2024 at 7:15 PM Asmaa Mnebhi <asmaa@xxxxxxxxxx>
> wrote:
> 
> > During Linux graceful reboot, the GPIO interrupts are not disabled.
> > Since the drivers are not removed during graceful reboot, the logic to
> > call mlxbf3_gpio_irq_disable() is not triggered.
> > Interrupts that remain enabled can cause issues on subsequent boots.
> >
> > For example, the mlxbf-gige driver contains PHY logic to bring up the link.
> > If the gpio-mlxbf3 driver loads first, the mlxbf-gige driver will use
> > a GPIO interrupt to bring up the link.
> > Otherwise, it will use polling.
> > The next time Linux boots and loads the drivers in this order, we
> encounter the issue:
> > - mlxbf-gige loads first and uses polling while the GPIO10
> >   interrupt is still enabled from the previous boot. So if
> >   the interrupt triggers, there is nothing to clear it.
> > - gpio-mlxbf3 loads.
> > - i2c-mlxbf loads. The interrupt doesn't trigger for I2C
> >   because it is shared with the GPIO interrupt line which
> >   was not cleared.
> >
> > The solution is to add a shutdown function to the GPIO driver to clear
> > and disable all interrupts. Also clear the interrupt after disabling it in
> mlxbf3_gpio_irq_disable().
> >
> > Fixes: 38a700efc510 ("gpio: mlxbf3: Add gpio driver support")
> > Signed-off-by: Asmaa Mnebhi <asmaa@xxxxxxxxxx>
> > Reviewed-by: David Thompson <davthompson@xxxxxxxxxx>
> 
> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> 
> Yours,
> Linus Walleij