From: Thierry Reding <thierry.reding@gmail.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Qipeng Zha <qipeng.zha@intel.com>,
linux-pwm@vger.kernel.org
Subject: Re: [PATCH 2/2] pwm: lpss: Rework the sequence of programming PWM_SW_UPDATE
Date: Wed, 16 Dec 2015 16:53:01 +0100 [thread overview]
Message-ID: <20151216155301.GG28947@ulmo> (raw)
In-Reply-To: <1447845918-66691-2-git-send-email-mika.westerberg@linux.intel.com>
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On Wed, Nov 18, 2015 at 01:25:18PM +0200, Mika Westerberg wrote:
> Setting of PWM_SW_UPDATE is bit different in Intel Broxton compared to the
> previous generation SoCs. Previously it was OK to set the bit many times
> (from userspace via sysfs for example) before the PWM is actually enabled.
>
> Starting from Intel Broxton it seems that we must set PWM_SW_UPDATE only
> once before the PWM is enabled. Otherwise it is possible that the PWM does
> not start properly.
>
> Change the sequence of how PWM_SW_UPDATE is programmed so that we only set
> it in pwm_lpss_config() when the PWM is already enabled. The initial
> setting of PWM_SW_UPDATE will be done when PWM gets enabled. This should
> make the driver work with the previous generation Intel SoCs and Broxton.
>
> Add also small delay after the bit is set to let the hardware propagate it
> properly.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---
> Applies on top of Qipeng's patch here:
>
> https://patchwork.ozlabs.org/patch/545313/
>
> drivers/pwm/pwm-lpss.c | 23 +++++++++++++++++++++--
> 1 file changed, 21 insertions(+), 2 deletions(-)
Applied, thanks.
Thierry
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next prev parent reply other threads:[~2015-12-16 15:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-18 11:25 [PATCH 1/2] pwm: lpss: select core part automatically Mika Westerberg
2015-11-18 11:25 ` [PATCH 2/2] pwm: lpss: Rework the sequence of programming PWM_SW_UPDATE Mika Westerberg
2015-12-16 15:53 ` Thierry Reding [this message]
2015-12-03 9:28 ` [PATCH 1/2] pwm: lpss: select core part automatically Mika Westerberg
2015-12-16 15:52 ` Thierry Reding
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