From: Marc Kleine-Budde <mkl@pengutronix.de>
To: Faiz Abbas <faiz_abbas@ti.com>,
wg@grandegger.com, robh+dt@kernel.org, mark.rutland@arm.com
Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
nsekhar@ti.com, fcooper@ti.com, robh@kernel.org,
Wenyou.Yang@microchip.com, sergei.shtylyov@cogentembedded.com
Subject: Re: [PATCH v6 3/6] can: m_can: Add PM Runtime
Date: Thu, 4 Jan 2018 16:18:02 +0100 [thread overview]
Message-ID: <31b6a902-19d9-2068-1028-b95dfba036bb@pengutronix.de> (raw)
In-Reply-To: <6bdaab16-cb16-e039-473c-52dd295bd4ba@ti.com>
[-- Attachment #1.1: Type: text/plain, Size: 3328 bytes --]
On 01/04/2018 04:17 PM, Faiz Abbas wrote:
> Hi,
>
> On Wednesday 03 January 2018 08:47 PM, Marc Kleine-Budde wrote:
>> On 01/03/2018 04:06 PM, Faiz Abbas wrote:
>>> Hi,
>>>
>>> On Wednesday 03 January 2018 07:55 PM, Marc Kleine-Budde wrote:
>>>> On 01/03/2018 01:39 PM, Faiz Abbas wrote:
>>>>> On Tuesday 02 January 2018 09:37 PM, Marc Kleine-Budde wrote:
>>>>>> On 12/22/2017 02:31 PM, Faiz Abbas wrote:
>>>>>>> From: Franklin S Cooper Jr <fcooper@ti.com>
>>>>>>>
>>>>>>> Add support for PM Runtime which is the new way to handle managing clocks.
>>>>>>> However, to avoid breaking SoCs not using PM_RUNTIME leave the old clk
>>>>>>> management approach in place.
>>>>>>
>>>>>> There is no PM_RUNTIME anymore since 464ed18ebdb6 ("PM: Eliminate
>>>>>> CONFIG_PM_RUNTIME")
>>>>>
>>>>> Ok. Will change the commit message.
>>>>>
>>>>>>
>>>>>> Have a look at the discussion: https://patchwork.kernel.org/patch/9436507/ :
>>>>>>
>>>>>>>> Well, I admit it would be nicer if drivers didn't have to worry about
>>>>>>>> whether or not CONFIG_PM was enabled. A slightly cleaner approach
>>>>>>>> from the one outlined above would have the probe routine do this:
>>>>>>>>
>>>>>>>> my_power_up(dev);
>>>>>>>> pm_runtime_set_active(dev);
>>>>>>>> pm_runtime_get_noresume(dev);
>>>>>>>> pm_runtime_enable(dev);
>>>>>
>>>>> This discussion seems to be about cases in which CONFIG_PM is not
>>>>> enabled. CONFIG_PM is always selected in the case of omap devices.
>>>>
>>>> Yes, but in the commit message you state that you need to support
>>>> systems that don't have PM_RUNTIME enabled. The only mainline SoCs I see
>>>> is "arch/arm/boot/dts/sama5d2.dtsi" so far. Please check if they select
>>>> CONFIG_PM, then we can make the driver much simpler.
>>>
>>> Actually the old clock management (for hclk which is the interface
>>> clock) is still required as mentioned in the cover letter. Will change
>>> the rather misleading description.
>>
>> Ok. So you can use the code as discussed on
>> https://patchwork.kernel.org/patch/9436507/ ?
>
> Looking at the kernel configuration, it seems like SAMA5D2 platform
> selects CONFIG_PM (Wenyou, please confirm). So, it seems like the only
> users of this driver always have CONFIG_PM enabled.
>
> So I guess the best way is to maintain the current code for pm_runtime_*
> and move the clock enable/disable to pm_runtime callbacks.
>
> Something like this:
>
> m_can_runtime_resume()
> {
> clk_prepare_enable(cclk);
> clk_prepare_enable(hclk);
> }
>
> m_can_runtime_suspend()
> {
> clk_disable_unprepare(cclk);
> clk_disable_unprepare(hclk);
> }
>
> SET_RUNTIME_PM_OPS(m_can_runtime_suspend, m_can_runtime_resume, NULL)
>
> static void m_can_start(struct net_device *dev)
> {
> pm_runtime_get_sync(dev)
> ...
> }
>
> static void m_can_stop(struct net_device *dev)
> {
> ...
> pm_runtime_put_sync(dev)
> }
>
> Does that sound okay? If yes, I will go work on the implementation.
ACK + error checking.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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next prev parent reply other threads:[~2018-01-04 15:18 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-22 13:31 [PATCH v6 0/6] Add M_CAN Support for Dra76 platform Faiz Abbas
2017-12-22 13:31 ` [PATCH v6 1/6] can: dev: Add support for limiting configured bitrate Faiz Abbas
2018-01-02 13:00 ` Marc Kleine-Budde
2018-01-03 12:19 ` Faiz Abbas
2018-01-02 16:15 ` Marc Kleine-Budde
2018-01-03 12:21 ` Faiz Abbas
2017-12-22 13:31 ` [PATCH v6 2/6] can: m_can: Add call to of_can_transceiver Faiz Abbas
2017-12-22 13:31 ` [PATCH v6 3/6] can: m_can: Add PM Runtime Faiz Abbas
2018-01-02 16:07 ` Marc Kleine-Budde
2018-01-03 12:39 ` Faiz Abbas
2018-01-03 14:25 ` Marc Kleine-Budde
2018-01-03 15:06 ` Faiz Abbas
2018-01-03 15:17 ` Marc Kleine-Budde
2018-01-04 15:17 ` Faiz Abbas
2018-01-04 15:18 ` Marc Kleine-Budde [this message]
2018-01-05 1:23 ` Yang, Wenyou
2017-12-22 13:31 ` [PATCH v6 4/6] can: m_can: Support higher speed CAN-FD bitrates Faiz Abbas
2018-01-02 13:35 ` Marc Kleine-Budde
2018-01-03 12:55 ` Faiz Abbas
2017-12-22 13:31 ` [PATCH v6 5/6] dt-bindings: can: m_can: Document new can transceiver binding Faiz Abbas
2017-12-22 13:31 ` [PATCH v6 6/6] dt-bindings: can: can-transceiver: Document new binding Faiz Abbas
2017-12-29 3:38 ` [PATCH v6 0/6] Add M_CAN Support for Dra76 platform Yang, Wenyou
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