linux-kernel - Re: [PATCH RESEND v2] gpio: omap: Add omap_gpio_disable/enable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAMRc=MexFELAEVpEg39teG=Yr-R71gwxRR9TtGDwHjVijzDeWA@mail.gmail.com>
Date: Wed, 6 Nov 2024 14:42:37 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Bin Liu <b-liu@...com>, Judith Mendez <jm@...com>, Kevin Hilman <khilman@...nel.org>, 
	Santosh Shilimkar <ssantosh@...nel.org>, Linus Walleij <linus.walleij@...aro.org>, 
	Bartosz Golaszewski <brgl@...ev.pl>, linux-omap@...r.kernel.org, linux-gpio@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH RESEND v2] gpio: omap: Add omap_gpio_disable/enable_irq calls

On Tue, Nov 5, 2024 at 8:00 PM Bin Liu <b-liu@...com> wrote:
>
> On Tue, Nov 05, 2024 at 12:47:58PM -0600, Judith Mendez wrote:
> > Hi Kevin,
> >
> > On 11/1/24 9:29 AM, Kevin Hilman wrote:
> > > Hi Judith,
> > >
> > > Judith Mendez <jm@...com> writes:
> > >
> > > > From: Bin Liu <b-liu@...com>
> > > >
> > > > Add omap_gpio_disable_irq and omap_gpio_enable_irq
> > > > calls in gpio-omap.
> > > >
> > > > Currently, kernel cannot disable gpio interrupts in
> > > > case of a irq storm, so add omap_gpio_disable/enable_irq
> > > > so that interrupts can be disabled/enabled.
> > > >
> > > > Signed-off-by: Bin Liu <b-liu@...com>
> > > > [Judith: Add commit message]
> > > > Signed-off-by: Judith Mendez <jm@...com>
> > >
> > > Thanks for this patch.  Can you give a bit more context on the
> > > problem(s) this solves and on which SoCs/platforms it was
> > > developed/validated?
> >
> > Sorry for the late response. Patch was tested/developed on am335x
> > device BBB, If you feed a PWM signal at 200KHz frequency to
> > GPIO, and execute gpiomon 0 12 &, Linux will be unresponsive
> > even after CTRL+C without these 2 functions in this patch. Once
> > this patch is applied, you can get console back after hitting
> > CTRL+C and then proceed to kill gpiomon.
>
> In addtion to Judith's explanation, when the PWM is applied to a GPIO
> pin, kernel detects the interrupt storm and disables the irq, however,
> without these callbacks, this gpio platform driver doesn't really
> disable the interrupt in the gpio controller, so the interrupt storm is
> still happening and handled by this gpio controller driver then causes
> Linux unresponsive.
>
> -Bin.

I take it that this is a fix then and should have relevant Fixes and Cc tags?

Bart