[Gta04-owner] [PATCH 1/2] mmc: core: allow a reset gpio to be configured.
ulf.hansson at linaro.org
Fri Nov 28 12:56:33 CET 2014
On 8 November 2014 at 01:14, NeilBrown <neilb at suse.de> wrote:
> If the regulator supplying an SDIO device is shared
> with another device, the turning the regulator 'on' and 'off'
> will not actually cycle power and so will not reset
> the device.
> This is particularly a problem for some wi2si wireless modules which
> have a BT module on chip and can share power lines.
> Without the power-cycle, subsequent reset commands fail.
> So allow a 'reset' gpio to be specified. If provided, the
> line is asserted during power-up.
There have been several attempts to fix similar issues as this patch
does. The latest one I posted a few month ago, which wasn't accepted.
There has also been some off-list discussions on especially how we
should describe this in DT and there were actually some consensus made
around that. Still I haven't seen any patches on the mailing lists.
So to summarize, I am really concerned that we keep having these power
sequence issues for SDIO devices and right now the discussion has been
on hold. I am considering to hack on it myself, since I am tired of
Regarding this patch, I don't intent to apply it.
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