From: robert.jarzmik@free•fr (Robert Jarzmik)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: PXA27x: fix workaround for AC97 reset
Date: Sun, 06 Jan 2013 15:07:37 +0100 [thread overview]
Message-ID: <87fw2ebe1i.fsf@free.fr> (raw)
In-Reply-To: <1357470761-14363-1-git-send-email-grinberg@compulab.co.il> (Igor Grinberg's message of "Sun, 6 Jan 2013 13:12:41 +0200")
Igor Grinberg <grinberg@compulab•co.il> writes:
> Fix the workaround to a hardware bug in the AC97 controller of PXA27x.
> A bug in the controller's warm reset functionality requires that the MFP
> used by the controller as the AC97_RESET_n line be temporarily
> reconfigured as a GPIO (AF0) and manually held high for the duration of
> the warm reset cycle.
>
> The workaround was broken long ago by commit fb1bf8cd
> ([ARM] pxa: introduce processor specific pxa27x_assert_ac97reset()).
> The commit above changed the original workaround code in a way that
> changed the MFP to AF0 (GPIO), but forgot to drive the GPIO high output.
> This way, the GPIO state was left input (and undriven) and only worked
> for boards with external pullup on the line.
>
> Fix the above breakage by actually configurring the GPIO for output high
> in case of reset assert and returning it to default state
> (AF2 and GPDR - input) in case of reset deassert.
NAK.
If you return GPIO95 to AF-input, the GPIO95 will be "KP_DKIN<2>", ie. you'll
map a keyboard input to a AC97 reset.
As I said in a mail before, don't put a AC97 reset line as an input pin, this is
not a sensible patch.
Cheers.
--
Robert
next prev parent reply other threads:[~2013-01-06 14:07 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-06 11:12 [PATCH] ARM: PXA27x: fix workaround for AC97 reset Igor Grinberg
2013-01-06 14:07 ` Robert Jarzmik [this message]
2013-01-06 16:24 ` Igor Grinberg
2013-01-06 16:48 ` [PATCH v2] " Igor Grinberg
2013-01-06 19:26 ` Mike Dunn
2013-01-06 22:19 ` Mike Dunn
2013-01-07 9:13 ` Igor Grinberg
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