From: Simon South <simon@simonsouth.net>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: tpiepho@gmail.com, u.kleine-koenig@pengutronix.de,
lee.jones@linaro.org, heiko@sntech.de, bbrezillon@kernel.org,
linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org
Subject: Re: [PATCH] pwm: rockchip: Eliminate potential race condition when probing
Date: Sat, 19 Dec 2020 15:32:06 -0500 [thread overview]
Message-ID: <875z4x5ygp.fsf@simonsouth.net> (raw)
In-Reply-To: <X9JfbpTnfqUVk6iN@ulmo> (Thierry Reding's message of "Thu, 10 Dec 2020 18:48:30 +0100")
Thierry, Trent and Robin, thanks for reviewing this and for your
comments. I think I understand a lot better now how this code needs to
work.
Trent Piepho <tpiepho@gmail.com> writes:
> Anyway, from the existing code, it seems clear that pc->pclk needs to
> be enabled for register access and pc->clk to generate a signal. The
> call to clk_prepare(pc->pclk) should become
> clk_prepare_enable(pc->pclk) and moved to before the enabled_conf
> check. Then clk_disable(pc->pclk) afterward.
I'll follow up with a revised set of patches that implement this. (I've
split it into multiple changes as they seem logically distinct and I
find the progression easier to see this way.)
--
Simon South
simon@simonsouth.net
WARNING: multiple messages have this Message-ID (diff)
From: Simon South <simon@simonsouth.net>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org, heiko@sntech.de,
bbrezillon@kernel.org, linux-rockchip@lists.infradead.org,
u.kleine-koenig@pengutronix.de, tpiepho@gmail.com,
lee.jones@linaro.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] pwm: rockchip: Eliminate potential race condition when probing
Date: Sat, 19 Dec 2020 15:32:06 -0500 [thread overview]
Message-ID: <875z4x5ygp.fsf@simonsouth.net> (raw)
In-Reply-To: <X9JfbpTnfqUVk6iN@ulmo> (Thierry Reding's message of "Thu, 10 Dec 2020 18:48:30 +0100")
Thierry, Trent and Robin, thanks for reviewing this and for your
comments. I think I understand a lot better now how this code needs to
work.
Trent Piepho <tpiepho@gmail.com> writes:
> Anyway, from the existing code, it seems clear that pc->pclk needs to
> be enabled for register access and pc->clk to generate a signal. The
> call to clk_prepare(pc->pclk) should become
> clk_prepare_enable(pc->pclk) and moved to before the enabled_conf
> check. Then clk_disable(pc->pclk) afterward.
I'll follow up with a revised set of patches that implement this. (I've
split it into multiple changes as they seem logically distinct and I
find the progression easier to see this way.)
--
Simon South
simon@simonsouth.net
_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
WARNING: multiple messages have this Message-ID (diff)
From: Simon South <simon@simonsouth.net>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org, heiko@sntech.de,
bbrezillon@kernel.org, linux-rockchip@lists.infradead.org,
u.kleine-koenig@pengutronix.de, tpiepho@gmail.com,
lee.jones@linaro.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] pwm: rockchip: Eliminate potential race condition when probing
Date: Sat, 19 Dec 2020 15:32:06 -0500 [thread overview]
Message-ID: <875z4x5ygp.fsf@simonsouth.net> (raw)
In-Reply-To: <X9JfbpTnfqUVk6iN@ulmo> (Thierry Reding's message of "Thu, 10 Dec 2020 18:48:30 +0100")
Thierry, Trent and Robin, thanks for reviewing this and for your
comments. I think I understand a lot better now how this code needs to
work.
Trent Piepho <tpiepho@gmail.com> writes:
> Anyway, from the existing code, it seems clear that pc->pclk needs to
> be enabled for register access and pc->clk to generate a signal. The
> call to clk_prepare(pc->pclk) should become
> clk_prepare_enable(pc->pclk) and moved to before the enabled_conf
> check. Then clk_disable(pc->pclk) afterward.
I'll follow up with a revised set of patches that implement this. (I've
split it into multiple changes as they seem logically distinct and I
find the progression easier to see this way.)
--
Simon South
simon@simonsouth.net
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-12-19 20:33 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-19 19:33 [PATCH v2] pwm: rockchip: Keep enabled PWMs running while probing Simon South
2020-09-19 19:33 ` Simon South
2020-09-19 19:33 ` Simon South
2020-09-21 8:01 ` Uwe Kleine-König
2020-09-21 8:01 ` Uwe Kleine-König
2020-09-21 8:01 ` Uwe Kleine-König
2020-09-23 10:49 ` Heiko Stübner
2020-09-23 10:49 ` Heiko Stübner
2020-09-23 10:49 ` Heiko Stübner
2020-09-23 11:41 ` Thierry Reding
2020-09-23 11:41 ` Thierry Reding
2020-09-23 11:41 ` Thierry Reding
2020-11-21 1:09 ` Trent Piepho
2020-11-21 1:09 ` Trent Piepho
2020-11-21 1:09 ` Trent Piepho
2020-11-30 0:36 ` Simon South
2020-11-30 0:36 ` Simon South
2020-11-30 0:36 ` Simon South
2020-11-30 0:44 ` [PATCH] pwm: rockchip: Eliminate potential race condition when probing Simon South
2020-11-30 0:44 ` Simon South
2020-11-30 0:44 ` Simon South
2020-12-10 17:48 ` Thierry Reding
2020-12-10 17:48 ` Thierry Reding
2020-12-10 17:48 ` Thierry Reding
2020-12-10 21:00 ` Trent Piepho
2020-12-10 21:00 ` Trent Piepho
2020-12-10 21:00 ` Trent Piepho
2020-12-11 10:44 ` Robin Murphy
2020-12-11 10:44 ` Robin Murphy
2020-12-11 10:44 ` Robin Murphy
2020-12-19 20:32 ` Simon South [this message]
2020-12-19 20:32 ` Simon South
2020-12-19 20:32 ` Simon South
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