From: Sean Young <sean@mess.org>
To: Stefan Wahren <wahrenst@gmx.net>
Cc: "Chris Morgan" <macroalpha82@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Rob Herring" <robh+dt@kernel.org>,
"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
"Conor Dooley" <conor+dt@kernel.org>,
andy.shevchenko@gmail.com,
"Angelo Compagnucci" <angelo.compagnucci@gmail.com>,
"Philip Howard" <phil@gadgetoid.com>,
"Linus Walleij" <linus.walleij@linaro.org>,
linux-pwm@vger.kernel.org, devicetree@vger.kernel.org,
linux-gpio@vger.kernel.org,
"Vincent Whitchurch" <vincent.whitchurch@axis.com>
Subject: Re: [PATCH V4 2/2] pwm: Add GPIO PWM driver
Date: Thu, 29 Feb 2024 08:57:27 +0000 [thread overview]
Message-ID: <ZeBG9wFVZBpYz9SS@gofer.mess.org> (raw)
In-Reply-To: <ZeBEQtI7rplfdpMT@gofer.mess.org>
On Thu, Feb 29, 2024 at 08:45:54AM +0000, Sean Young wrote:
> On Tue, Feb 27, 2024 at 05:59:40PM +0100, Stefan Wahren wrote:
> > Hi Chris,
> >
> > Am 27.02.24 um 16:32 schrieb Chris Morgan:
> > > I have a series of devices with GPIO controlled force feedback that
> > > this driver helps us control better. So I'm looking forward to this,
> > > thank you.
> > Thanks for testing. I didn't had much time recently and i was fighting
> > with hr timer resolution stuff. But will try to send the next version in
> > March.
> > > Note that when I set the resolution too low (I got confused and set
> > > the period to 255) my device locked up hard and only a forced
> > > power cycle could bring it back.
> > Unfortunately this is a general design issue by driving the GPIO by a
> > kernel driver and "expected" behavior. I didn't have a good solution for
> > it yet.
>
> When we reprogram the timer with hrtimer_forward(), we could check whether
> we have overrun - i.e. we are already beyond the expires time. This could
> be a hint that a) we cannot generate the pwm signal and b) this might
> be what causes the hang, because we are returning HRTIMER_RESTART yet
> no new expires has been programmed.
I mean something like:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/media/rc/pwm-ir-tx.c#n144
Sean
next prev parent reply other threads:[~2024-02-29 8:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-04 22:08 [PATCH V4 0/2] pwm: Add GPIO PWM driver Stefan Wahren
2024-02-04 22:08 ` [PATCH V4 1/2] dt-bindings: pwm: Add pwm-gpio Stefan Wahren
2024-02-04 22:47 ` Linus Walleij
2024-02-05 5:58 ` Dhruva Gole
2024-02-05 7:44 ` Krzysztof Kozlowski
2024-02-05 9:15 ` Uwe Kleine-König
2024-02-05 11:58 ` Stefan Wahren
2024-02-04 22:08 ` [PATCH V4 2/2] pwm: Add GPIO PWM driver Stefan Wahren
2024-02-04 22:50 ` Linus Walleij
2024-02-05 6:11 ` Dhruva Gole
2024-02-05 7:16 ` Stefan Wahren
2024-02-05 10:09 ` Uwe Kleine-König
2024-02-05 12:21 ` Stefan Wahren
2024-02-27 15:32 ` Chris Morgan
2024-02-27 16:59 ` Stefan Wahren
2024-02-28 12:43 ` Phil Howard
2024-02-29 8:45 ` Sean Young
2024-02-29 8:57 ` Sean Young [this message]
2024-02-27 16:41 ` Andy Shevchenko
2024-02-27 20:24 ` Stefan Wahren
2024-02-27 20:47 ` Andy Shevchenko
2024-02-28 18:06 ` Stefan Wahren
2024-02-05 5:55 ` [PATCH V4 0/2] " Dhruva Gole
2024-02-05 7:08 ` Stefan Wahren
2024-02-05 13:06 ` Phil Howard
2024-05-27 8:22 ` Linus Walleij
2024-05-27 8:44 ` Stefan Wahren
2024-05-27 9:56 ` Linus Walleij
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