linux-kernel - Re: [PATCH 0/2] pwm: meson: two small bug-fixes

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Message-ID: <20190509145259.GA8907@ulmo>
Date:   Thu, 9 May 2019 16:52:59 +0200
From:   Thierry Reding <thierry.reding@...il.com>
To:     Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Cc:     linux-pwm@...r.kernel.org, linux-amlogic@...ts.infradead.org,
        narmstrong@...libre.com, jbrunet@...libre.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        u.kleine-koenig@...gutronix.de, bichao.zheng@...ogic.com
Subject: Re: [PATCH 0/2] pwm: meson: two small bug-fixes

On Mon, Apr 01, 2019 at 08:18:15PM +0200, Martin Blumenstingl wrote:
> This series applies on top of my other fix "pwm: meson: fix scheduling
> while atomic issue" from [0]
> 
> The first patch fixes an issue where the maximum possible pre-divider
> (128) could not be used because there was an off-by-one error in the
> code. I discovered this while testing with the longest supported period
> (349514407ns) when running from XTAL. This is verified to work on my
> Meson8b Odroid-C1 board using "pwm_b" on GPIOX_11.
> 
> The second patch was suggested by Uwe Kleine-König but was actually
> implemented much earlier (back in mid 2018) by Bichao Zheng from
> Amlogic. This patch fixes changing the duty cycle by relying on the
> hardware to re-start the PWM output (instead of adding an artificial
> "constant LOW" of about 20ms - as measured by Bichao Zheng when
> stopping and re-starting the PWM output from within the driver). I
> tested this fix on my Meson8b Odroid-C1 board which uses a PWM driven
> CPU regulator (DVFS with all supported OPPs is still working fine for
> me, although I couldn't observe any issues before this patch).
> 
> I also have some code-improvements queued which I'll send in the next
> days, see [1]
> 
> 
> [0] https://patchwork.kernel.org/cover/10880419/
> [1] https://github.com/xdarklight/linux/commits/meson-pwm-for-5.2-v1
> 
> 
> Bichao Zheng (1):
>   pwm: meson: don't disable pwm when setting duty repeatedly
> 
> Martin Blumenstingl (1):
>   pwm: meson: consider 128 a valid pre-divider
> 
>  drivers/pwm/pwm-meson.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)

Both patches applied, thanks.

Thierry

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