Re: [PATCH] mmc: use usleep_range() in mmc_delay()

From: Aaro Koskinen
Date: Fri Jan 13 2012 - 09:55:39 EST


Hi,

On Fri, 13 Jan 2012, Dmitry Antipov wrote:
On 01/13/2012 05:22 PM, Aaro Koskinen wrote:

Anyway, I think the change is good. On systems with multiple MMC devices
the boot/probe can spend 100-200 ms alone just doing busylooping delays. I
think e.g. in mmc_rescan() the code uses frequently mmc_delay(10).

I'm worrying about this:

mmc_delay(DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000))

since I have no ideas about typical values for this timeout.
If it may be too small (<=10 us), using usleep_range() makes no sense.

Hmm, but the code above is rounding it up to at least 1 ms?

A.
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