From: Simon Horman <horms@verge.net.au>
To: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
linux-mmc@vger.kernel.org, linux-sh@vger.kernel.org
Subject: Re: [PATCH v2] mmc: tmio: Don't access hardware registers after stopping clocks
Date: Wed, 20 Jun 2012 02:23:15 +0000 [thread overview]
Message-ID: <20120620022312.GA898@verge.net.au> (raw)
In-Reply-To: <87ehpir0rl.wl%kuninori.morimoto.gx@renesas.com>
On Wed, Jun 13, 2012 at 09:11:13PM -0700, Kuninori Morimoto wrote:
>
> Laurent Pinchart wrote:
> >
> > The tmio_mmc_set_ios() function configures the MMC power, clock and bus
> > width. When the mmc core requests the driver to power off the card, we
> > inform runtime PM, that the controller can be suspended. This can lead
> > to the MSTP clock being turned off.
> >
> > Writing to any 16-bit hardware registers with the MSTP clock off leads
> > to timeouts and errors being printed to the kernel log. This can occur
> > both when stopping the MMC clock and when configuring the bus width.
> >
> > To fix this, stop the MMC clock before calling put_runtime_pm(), and
> > skip bus width configuration when power is off.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
>
> This patch solved kzm9g MicroSD hang-up issue.
>
> Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Yes, it solves that issue for me too.
Tested-by: Simon Horman <horms@verge.net.au>
prev parent reply other threads:[~2012-06-20 2:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-12 21:29 [PATCH v2] mmc: tmio: Don't access hardware registers after stopping clocks Laurent Pinchart
2012-06-13 1:17 ` Simon Horman
2012-06-13 7:42 ` Laurent Pinchart
2012-06-13 13:27 ` Guennadi Liakhovetski
2012-06-20 6:22 ` Chris Ball
2012-06-14 4:11 ` Kuninori Morimoto
2012-06-20 2:23 ` Simon Horman [this message]
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