Re: [PATCH] Two fixes for my mmc/sd cardreader

Maxim Levitsky
2010-06-21T19:21:44Z

On Fri, 2010-06-18 at 00:21 +0300, Maxim Levitsky wrote:
> Hi,
>
> These are 2 fixes for my card reader.
>
>
> First patch fixes old issue with system hand on suspend to disk/ram with
> mmc card inserted.
> I updated description, and pm notification registration order.
> I think this patch can an should go to 2.6.35, because it fixes long
> standing and nasty regression.
>
> The second patch is a result of my work trying to understand why my card
> reader sometimes dies on resume.
> This reader has a special MMC function which steals MMC cards, and until
> now had no driver. A way to disable it was found, and while it works, it
> has (at least here) a side effect of killing the controller on resume
> from ram/disk (and it happens often, and doesn't depend of whether card
> was in slot or not during suspend).
>
> Fortunately it turned out that MMC part is _almost_ standard SDHCI
> controller.
> This patch adds support for this device to standard sdhci driver.
> Unfortunately, this support still contais small hack.
> It waits 1/2 of a second on resume before initializing the controller.
> Not doing so, and resuming with MMC card present results in confused
> controller. It is not dead though. A card reinsert makes it work again
> with all cards.
> Yet the 1st patch is must for this because otherwise mmc core seeing
> that controller doesn't respond, removes the card, therefore hangs the
> system.
> It doesn't happen when I wait these 1/2 of second though.
>
> I think that this patch is also ok for 2.6.35, because it only adds new
> functionality.
> You are free to disable MMC controller using the same
> CONFIG_MMC_RICOH_MMC.
>
> If you don't disable it though, instead of full lack of functionality
> you will get full featured MMC controller.
>
> Best regards,
> Maxim Levitsky
>
>
>
ping