From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Simon South <simon@simonsouth.net>
Cc: linux-pwm@vger.kernel.org, heiko@sntech.de,
bbrezillon@kernel.org, lee.jones@linaro.org,
linux-rockchip@lists.infradead.org, thierry.reding@gmail.com,
tpiepho@gmail.com, robin.murphy@arm.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 1/7] pwm: rockchip: Enable APB clock during register access while probing
Date: Wed, 13 Jan 2021 08:23:58 +0100 [thread overview]
Message-ID: <20210113072358.7ozcznyjyhuh2mt4@pengutronix.de> (raw)
In-Reply-To: <49ceda3def13f6186073745e99d7315c974bfa81.1608735481.git.simon@simonsouth.net>
[-- Attachment #1.1: Type: text/plain, Size: 1137 bytes --]
Hello Simon,
On Wed, Dec 23, 2020 at 11:01:03AM -0500, Simon South wrote:
> Commit 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while
> probing") modified rockchip_pwm_probe() to access a PWM device's registers
> directly to check whether or not the device is running, but did not also
> change the function to first enable the device's APB clock to be certain
> the device can respond. This risks hanging the kernel on systems with PWM
> devices that use more than a single clock.
>
> Avoid this by enabling the device's APB clock before accessing its
> registers (and disabling the clock when register access is complete).
>
> Fixes: 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while probing")
> Reported-by: Thierry Reding <thierry.reding@gmail.com>
> Suggested-by: Trent Piepho <tpiepho@gmail.com>
> Signed-off-by: Simon South <simon@simonsouth.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Thanks
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
[-- Attachment #2: Type: text/plain, Size: 176 bytes --]
_______________________________________________
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:[~2021-01-13 7:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-23 16:01 [PATCH v3 0/7] pwm: rockchip: Eliminate potential race condition when probing Simon South
2020-12-23 16:01 ` [PATCH v3 1/7] pwm: rockchip: Enable APB clock during register access while probing Simon South
2021-01-13 7:23 ` Uwe Kleine-König [this message]
2020-12-23 16:01 ` [PATCH v3 2/7] pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare() Simon South
2021-01-13 7:31 ` Uwe Kleine-König
2020-12-23 16:01 ` [PATCH v3 3/7] pwm: rockchip: Replace "bus clk" with "PWM clk" Simon South
2021-01-13 7:33 ` Uwe Kleine-König
2020-12-23 16:01 ` [PATCH v3 4/7] pwm: rockchip: Eliminate potential race condition when probing Simon South
2021-01-13 7:37 ` Uwe Kleine-König
2020-12-23 16:01 ` [PATCH v3 5/7] pwm: rockchip: rockchip_pwm_probe(): Remove unneeded goto target Simon South
2021-01-13 7:38 ` Uwe Kleine-König
2020-12-23 16:01 ` [PATCH v3 6/7] pwm: rockchip: Enable PWM clock of probed device only if running Simon South
2021-01-13 7:50 ` Uwe Kleine-König
2021-01-14 15:22 ` Simon South
2020-12-23 16:01 ` [PATCH v3 7/7] pwm: rockchip: Enable clock before calling clk_get_rate() Simon South
2021-01-13 7:54 ` Uwe Kleine-König
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210113072358.7ozcznyjyhuh2mt4@pengutronix.de \
--to=u.kleine-koenig@pengutronix.de \
--cc=bbrezillon@kernel.org \
--cc=heiko@sntech.de \
--cc=lee.jones@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-pwm@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=robin.murphy@arm.com \
--cc=simon@simonsouth.net \
--cc=thierry.reding@gmail.com \
--cc=tpiepho@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).