From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: George Stark <GNStark@sberdevices.ru>
Cc: "thierry.reding@gmail.com" <thierry.reding@gmail.com>,
"krzysztof.kozlowski@linaro.org" <krzysztof.kozlowski@linaro.org>,
"alim.akhtar@samsung.com" <alim.akhtar@samsung.com>,
"linux-pwm@vger.kernel.org" <linux-pwm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-samsung-soc@vger.kernel.org"
<linux-samsung-soc@vger.kernel.org>,
kernel <kernel@sberdevices.ru>
Subject: Re: [RFC PATCH v1] Revert "pwm: Clear chip_data in pwm_put()"
Date: Wed, 8 Mar 2023 17:52:02 +0100 [thread overview]
Message-ID: <20230308165202.gaeziqdncbkeo5l6@pengutronix.de> (raw)
In-Reply-To: <cc73a82d-89fa-1edf-650a-a1a3824cc791@sberdevices.ru>
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Hello George,
On Wed, Mar 08, 2023 at 12:16:00PM +0000, George Stark wrote:
> On 3/8/23 00:28, Uwe Kleine-König wrote:
> > If you ask me, better drop pwm_set_chip_data() completely. It adds no
> > useful value. It's just a variant of driver data and using both
> > complicates the driver and probably fragments memory allocations. Also
> > the sematic of driver data is better known as it's the same for all
> > subsystems.
> >
> > Do you use the capture functionality? In my eyes the capture part of the
> > pwm subsystem is very alien. Only a small subset of the hardware
> > supports this and the counter framework should be better suited for such
> > tasks.
> I don't use pwm-sti driver. I update meson pwm driver for new chips
> and when started using pwm_set_chip_data in probe I was very surprised that
> my data is lost after sysfs export/unexport calls. Then I found the
> patch and
> checked other drivers for similar usecases.
OK.
> Probably you're right about dropping pwm_set_chip_data.
If you want to tackle that, you might want to take
https://lore.kernel.org/all/20210504132537.62072-2-u.kleine-koenig@pengutronix.de/
into account. (Both to reuse this patch to prepare pwm-berlin for
dropping pwm_set_chip_data and to be prepared that back then Thierry
opposed to the idea.)
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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prev parent reply other threads:[~2023-03-08 16:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-07 21:00 [RFC PATCH v1] Revert "pwm: Clear chip_data in pwm_put()" George Stark
2023-03-07 21:27 ` Uwe Kleine-König
2023-03-08 12:16 ` George Stark
2023-03-08 16:52 ` Uwe Kleine-König [this message]
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