[PATCH] gpio/generic: initialize the shadow of direction register

From: LW@KARO-electronics.de (Lothar Waßmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] gpio/generic: initialize the shadow of direction register
Date: Wed, 16 May 2012 15:54:37 +0200	[thread overview]
Message-ID: <20403.45469.121234.808145@ipc1.ka-ro> (raw)
In-Reply-To: <CAAQ0ZWRpm8mrBnseepV17QMGZcz3W=vw4yYJR5UvSGg2i5dvgg@mail.gmail.com>

Hi,

Shawn Guo writes:
> On 16 May 2012 15:34, Lothar Wa?mann <LW@karo-electronics.de> wrote:
> > You initialize a variable to a specific value that defaulted to zero
> > before.
> >
> The variable defaulted to zero is causing a problem.  I'm fixing that problem.
> 
Actually I had sent a similar patch in July last year which was
rejected with the following reasoning:

| I don't know if this is a valid thing to do or not. Not every GPIO
| controller supports reading back the initial state from the direction
| register. I suspect it is better to leave initialization of the
| direction to the gpio controller driver itself.

See: http://lkml.indiana.edu/hypermail/linux/kernel/1107.0/00908.html

That's why I came up with the patch to gpio-mxc.c

Lothar Wa?mann
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