From: Felipe Balbi <balbi@kernel.org>
To: Mike Looijmans <mike.looijmans@topic.nl>,
Mark Brown <broonie@kernel.org>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
gregkh@linuxfoundation.org, lgirdwood@gmail.com
Subject: Re: [PATCH v3] usb: dwc3: Add support for VBUS power control
Date: Mon, 07 Sep 2020 10:44:55 +0300 [thread overview]
Message-ID: <87a6y21154.fsf@kernel.org> (raw)
In-Reply-To: <be4013b6-01c6-7f67-35ad-5c398b85c066@topic.nl>
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Hi,
Mike Looijmans <mike.looijmans@topic.nl> writes:
> Met vriendelijke groet / kind regards,
>
> Mike Looijmans
> System Expert
>
>
> TOPIC Embedded Products B.V.
> Materiaalweg 4, 5681 RJ Best
> The Netherlands
>
> T: +31 (0) 499 33 69 69
> E: mike.looijmans@topicproducts.com
> W: www.topicproducts.com
>
> Please consider the environment before printing this e-mail
> On 27-07-2020 12:23, Mark Brown wrote:
>> On Sun, Jul 26, 2020 at 09:10:39AM +0200, Mike Looijmans wrote:
>>> On 23-07-2020 13:05, Mark Brown wrote:
>>
>>>> Does the device actually support running without power so that's a thing
>>>> that can happen? _get_optional() should only ever be used for supplies
>>>> that may be physically absent.
>>
>>> It's the 5V VBUS power for the USB "plug" that's being controlled here. It
>>> must turned on when the controller is in "host" mode. Some boards arrange
>>> this in hardware through the PHY, and some just don't have any control at
>>> all and have it permanently on or off. On a board where the 5V is controlled
>>> using a GPIO line or an I2C chip, this patch is required to make it work.
>>
>> That sounds like the driver should not be using _get_optional() then.
>>
>
> Making it mandatory would break most (read: all except Topic's) existing
> boards as they won't have it in their devicetree. I'm perfectly okay with
> that, but others might disagree.
you're perfectly okay with break all existing users of the driver?
That's a bit harsh
--
balbi
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next prev parent reply other threads:[~2020-09-07 7:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-19 14:25 [PATCH v3] usb: dwc3: Add support for VBUS power control Mike Looijmans
2020-07-23 7:56 ` Vincent Whitchurch
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.949ef384-8293-46b8-903f-40a477c056ae.2698920d-90ba-4c46-abda-83e18e2093c8@emailsignatures365.codetwo.com>
2020-07-23 11:05 ` Mark Brown
2020-07-26 7:10 ` Mike Looijmans
2020-07-27 10:23 ` Mark Brown
2020-07-27 11:50 ` Mike Looijmans
2020-07-27 11:53 ` Mark Brown
2020-07-28 7:29 ` Mike Looijmans
2020-09-07 7:44 ` Felipe Balbi [this message]
2020-09-07 7:50 ` Mike Looijmans
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