Re: [PATCH 3/3] mmc: sdhci-pci: allow 8-bit bus width for Intel PCH

From: Alexander Stein
Date: Wed Mar 14 2012 - 03:26:21 EST


Hello Tomoya,

Am Mittwoch, 14. März 2012, 10:17:35 schrieb Tomoya MORINAGA:
> Hi Alexander
>
> As a matter of interest,
> do you mean that current MMC of eg20t on Linux doesn't support 8-bit access?

We have a board with an 8-bit connected eMMC and Linux only used 4-bit wide
bus access. After some research IMO the device is only matched to the default
PCI id class
> PCI_DEVICE_CLASS((PCI_CLASS_SYSTEM_SDHCI << 8), 0xFFFF00)

AFAICS it's the same issue with the Medfield eMMC where 8-bit bus support is
added in 0d013bcf5c272faea1f8e7a5ef3cb2e98103d5cb
This also states the default is 4-bit bus width which I saw before.

Regards,
Alexander
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