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From: Stefan Wahren <stefan.wahren@i2se.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Thierry Reding" <thierry.reding@gmail.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>,
	Shawn Guo <shawn.guo@freescale.com>,
	linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] pwm: mxs: set pwm_chip can_sleep flag
Date: Fri, 25 Apr 2014 16:11:11 +0200	[thread overview]
Message-ID: <535A6CFF.2020800@i2se.com> (raw)
In-Reply-To: <20140409143516.GW29751@pengutronix.de>

Hi,

Am 09.04.2014 16:35, schrieb Uwe Kleine-König:
> Hello,
>
> On Wed, Apr 09, 2014 at 12:46:53PM +0200, Thierry Reding wrote:
>>
>> My preference would be simply d). Mostly because I don't like special
>> cases and especially because I don't see an advantage in special casing
>> 0 and full period duty cycles. That doesn't mean of course that drivers
>> can't special case if they really want or have to.
> Well d' is just an optimisation, because if you have a duty cycle
> between 0 and full (exclusive) and no other means of syncronisation
> you cannot influence where pwm_disable stops the output, at low or high.
>
> Do we have cases where pwm_disable makes the pin high-z? Or something
> else which violates the assumption "pwm_config(pwm, 0, period);
> pwm_disable(pwm); makes the pin 0"?
>  
>> That said I've also been thinking about adding support for e), which
>> would allow atomically changing the duty cycle, period and polarity of a
>> channel. This might become necessary at some point.
> On i.MX28 you cannot change atomically, only program atomically. The
> current period will end regularily anyhow as programmed before. But
> maybe that's what you mean?!
>
> Best regards
> Uwe
>

i want to ask gently, if somebody working on this issue?

Regards,
Stefan Wahren

WARNING: multiple messages have this Message-ID (diff)
From: stefan.wahren@i2se.com (Stefan Wahren)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] pwm: mxs: set pwm_chip can_sleep flag
Date: Fri, 25 Apr 2014 16:11:11 +0200	[thread overview]
Message-ID: <535A6CFF.2020800@i2se.com> (raw)
In-Reply-To: <20140409143516.GW29751@pengutronix.de>

Hi,

Am 09.04.2014 16:35, schrieb Uwe Kleine-K?nig:
> Hello,
>
> On Wed, Apr 09, 2014 at 12:46:53PM +0200, Thierry Reding wrote:
>>
>> My preference would be simply d). Mostly because I don't like special
>> cases and especially because I don't see an advantage in special casing
>> 0 and full period duty cycles. That doesn't mean of course that drivers
>> can't special case if they really want or have to.
> Well d' is just an optimisation, because if you have a duty cycle
> between 0 and full (exclusive) and no other means of syncronisation
> you cannot influence where pwm_disable stops the output, at low or high.
>
> Do we have cases where pwm_disable makes the pin high-z? Or something
> else which violates the assumption "pwm_config(pwm, 0, period);
> pwm_disable(pwm); makes the pin 0"?
>  
>> That said I've also been thinking about adding support for e), which
>> would allow atomically changing the duty cycle, period and polarity of a
>> channel. This might become necessary at some point.
> On i.MX28 you cannot change atomically, only program atomically. The
> current period will end regularily anyhow as programmed before. But
> maybe that's what you mean?!
>
> Best regards
> Uwe
>

i want to ask gently, if somebody working on this issue?

Regards,
Stefan Wahren

  reply	other threads:[~2014-04-25 14:11 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-08 11:29 [PATCH] pwm: mxs: set pwm_chip can_sleep flag Shawn Guo
2014-04-08 11:29 ` Shawn Guo
2014-04-08 13:46 ` Stefan Wahren
2014-04-08 13:46   ` Stefan Wahren
2014-04-08 14:18   ` Alexandre Belloni
2014-04-08 14:18     ` Alexandre Belloni
2014-04-08 16:53     ` Stefan Wahren
2014-04-08 16:53       ` Stefan Wahren
2014-04-08 23:16       ` Alexandre Belloni
2014-04-08 23:16         ` Alexandre Belloni
2014-04-08 23:44         ` Russell King - ARM Linux
2014-04-08 23:44           ` Russell King - ARM Linux
2014-04-09  3:41           ` Shawn Guo
2014-04-09  3:41             ` Shawn Guo
2014-04-09  8:39             ` Russell King - ARM Linux
2014-04-09  8:39               ` Russell King - ARM Linux
2014-04-08 17:59   ` Uwe Kleine-König
2014-04-08 17:59     ` Uwe Kleine-König
2014-04-08 23:42     ` Alexandre Belloni
2014-04-08 23:42       ` Alexandre Belloni
2014-04-09  8:23       ` Uwe Kleine-König
2014-04-09  8:23         ` Uwe Kleine-König
2014-04-09 10:03         ` Alexandre Belloni
2014-04-09 10:03           ` Alexandre Belloni
2014-04-09 10:46           ` Thierry Reding
2014-04-09 10:46             ` Thierry Reding
2014-04-09 14:35             ` Uwe Kleine-König
2014-04-09 14:35               ` Uwe Kleine-König
2014-04-25 14:11               ` Stefan Wahren [this message]
2014-04-25 14:11                 ` Stefan Wahren
2014-04-08 14:24 ` Alexandre Belloni
2014-04-08 14:24   ` Alexandre Belloni
2014-04-08 17:26 ` Stefan Wahren
2014-04-08 17:26   ` Stefan Wahren

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