From: Arnd Bergmann <arnd@arndb.de>
To: Chuanxiao Dong <chuanxiao.dong@intel.com>
Subject: Re: [PATCH v4 2/3]mmc: enable TRIM/ERASE caps for SDHCI host
Date: Sat, 12 Feb 2011 09:34:04 +0100
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        akpm@linux-foundation.org, adrian.hunter@nokia.com
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On Saturday 12 February 2011 07:22:20 Chuanxiao Dong wrote:
> SDHCI host controller has TRIM/ERASE capability, enable these caps for erasing
> purpose.
> 
> ERASE command needs R1B response. So for such command with busy signal, before
> sending command, SDHCI host driver will simply set a maximum value for timeout
> control register which is safe to use.
> 
> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>

Great stuff! I needed this for a project of mine, but couldn't
get it to work reliably without knowing about the timeout logic.

I think, almost no mmc controllers advertice MMC_CAP_ERASE today,
which is a real shame, given that it's extremely useful for performance.

	Arnd
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