From: Lee Jones <lee.jones@linaro.org>
To: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Cc: vilhelm.gray@gmail.com, alexandre.torgue@foss.st.com,
mcoquelin.stm32@gmail.com, olivier.moysan@foss.st.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [PATCH] mfd: stm32-timers: avoid clearing auto reload register
Date: Tue, 23 Mar 2021 09:39:56 +0000 [thread overview]
Message-ID: <20210323093956.GS2916463@dell> (raw)
In-Reply-To: <1614793895-10504-1-git-send-email-fabrice.gasnier@foss.st.com>
On Wed, 03 Mar 2021, Fabrice Gasnier wrote:
> The ARR register is cleared unconditionally upon probing, after the maximum
> value has been read. This initial condition is rather not intuitive, when
> considering the counter child driver. It rather expects the maximum value
> by default:
> - The counter interface shows a zero value by default for 'ceiling'
> attribute.
> - Enabling the counter without any prior configuration makes it doesn't
> count.
>
> The reset value of ARR register is the maximum. So Choice here
> is to backup it, and restore it then, instead of clearing its value.
> It also fixes the initial condition seen by the counter driver.
>
> Fixes: d0f949e220fd ("mfd: Add STM32 Timers driver")
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
> ---
> drivers/mfd/stm32-timers.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
Applied, thanks.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
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prev parent reply other threads:[~2021-03-23 9:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-03 17:51 [PATCH] mfd: stm32-timers: avoid clearing auto reload register Fabrice Gasnier
2021-03-03 23:45 ` William Breathitt Gray
2021-03-22 10:59 ` Fabrice Gasnier
2021-03-22 12:56 ` Lee Jones
2021-03-23 9:39 ` Lee Jones [this message]
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