linux-kernel - Re: [PATCHv1 0/6] leds: pca9653x: support inverted outputs and cleanups

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Message-ID: <CAPybu_2uZqR4exnS08taVYyr=ziK+EzuJy+_FxhbtqSiOE_=mw@mail.gmail.com>
Date:	Tue, 19 Apr 2016 15:42:51 +0200
From:	Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
To:	Olliver Schinagl <oliver@...inagl.nl>
Cc:	Jacek Anaszewski <j.anaszewski@...sung.com>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Richard Purdie <rpurdie@...ys.net>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux LED Subsystem <linux-leds@...r.kernel.org>,
	Peter Meerwald <pmeerw@...erw.net>
Subject: Re: [PATCHv1 0/6] leds: pca9653x: support inverted outputs and cleanups

Hi again

On Tue, Apr 19, 2016 at 3:27 PM, Olliver Schinagl <oliver@...inagl.nl> wrote:
> Hey Ricardo,

> Without actually looking at the code right now, but the driver does a
> read/modify/write on the register, and a register is shared among several
> leds. So in that regard, it makes sense and I don't think it's very
> expensive to move the lock, since we have to lock for the write a few lines
> down anyway.

Actually, the code is only making sure that PCA963X_MODE2_DMBLNK is
on. It is never cleared afterwards.

It will be great if you could set that bit on probe and remove those
two lines and verify that it works on real hardware.


The move of the lock can be a bit expensive. i2c writes can take a
while to be performed, this is why only ledout was protected
initially.

Best regards