Re: [PATCH] MMC: Clean up low voltage range handling

From: Pierre Ossman
Date: Sun Mar 11 2007 - 19:40:27 EST

Philip Langdale wrote:
> Clean up the handling of low voltage MMC cards.
> The latest MMC and SD specs both agree that the low
> voltage range is defined as 1.65-1.95V and is signified
> by bit 7 in the OCR. An old Sandisk spec implied that
> bits 7-0 represented voltages below 2.0V in 1V increments,
> and the code was accordingly written with that expectation.

We must not have the same specs. My simplified SD 2.0 physical spec
defines everything below bit 15 as reserved.

> This change switches the code to conform to the specs and
> fixes the SDHCI driver. It also removes the explicit
> defines for the host vdd and updates the SDHCI driver
> to convert the bit number back to the mask value
> for comparisons. Having only a single set of defines
> ensures there's nothing to get out of sync.

Although this is a nice change, it confuses things to have two changes
in one commit. Could you split them up and base it on my "for-andrew"


-- Pierre Ossman

Linux kernel, MMC maintainer
PulseAudio, core developer
rdesktop, core developer

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