Re: [PATCH v6 3/6] can: m_can: Add PM Runtime - Marc Kleine-Budde

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: Wed, 3 Jan 2018 16:17:09 +0100	[thread overview]
Message-ID: <cb306ae5-87c5-f6ef-0c40-3b47e208d256@pengutronix.de> (raw)
In-Reply-To: <a45431f2-d262-39a1-9152-a2ff75560d21@ti.com>

[-- Attachment #1.1: Type: text/plain, Size: 2157 bytes --]

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/ ?

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   |

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]