linux-kernel - Re: [PATCH 1/2] leds: Add flag to keep trigger always

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Message-ID: <20190930133902.GA2249614@kroah.com>
Date:   Mon, 30 Sep 2019 15:39:02 +0200
From:   Greg KH <gregkh@...uxfoundation.org>
To:     Pavel Machek <pavel@....cz>
Cc:     Guru Das Srinagesh <gurus@...eaurora.org>,
        linux-leds@...r.kernel.org,
        Jacek Anaszewski <jacek.anaszewski@...il.com>,
        Dan Murphy <dmurphy@...com>, linux-kernel@...r.kernel.org,
        Subbaraman Narayanamurthy <subbaram@...eaurora.org>
Subject: Re: [PATCH 1/2] leds: Add flag to keep trigger always

On Sat, Aug 10, 2019 at 09:13:22AM +0200, Pavel Machek wrote:
> On Fri 2019-08-09 17:52:46, Guru Das Srinagesh wrote:
> > From: Subbaraman Narayanamurthy <subbaram@...eaurora.org>
> > 
> > Commit 0013b23d66a2768f5babbb0ea9f03ab067a990d8 ("leds: disable triggers
> > on brightness set") removes the trigger on an LED class device when
> > brightness is set to 0. However, there are some LED class devices which
> > need the trigger not to be removed. In a use case like camera flash,
> > camera flash driver passes in a trigger device to LED class driver. If
> > the trigger is removed when the brightness is set to 0, this will affect
> > the clients using those triggers. Hence add a flag to always keep the
> > trigger even when brightness is set to 0.
> 
> No.
> 
> Yes, it would affect those clients. Don't do it, then. It is
> root-only operation.

I don't understand.  The original commit broke userspace operations.
Shouldn't it be reverted, or fixed this way in order to have userspace
work properly again?

thanks,

greg k-h