Subject: [PATCH] mmc: omap_hsmmc: Add support for Erratum 2.1.1.128 in device tree boot

From: [email-masked] (Nishanth Menon)
Date: Tue, 21 Jan 2014 11:38:00 -0600

On 01/20/2014 05:39 PM, Felipe Balbi wrote:
> On Mon, Jan 20, 2014 at 05:29:02PM -0600, Nishanth Menon wrote:
>> When device is booted using devicetree, platforms impacted by
>> Erratum 2.1.1.128 is not detected easily in the mmc driver. This erratum
>> indicates that the module cannot do multi-block transfers.
>>
>> Handle this by providing a boolean flag to indicate to driver that it is
>> working on a hardware with mentioned limitation.
> 
> sure there's no way of reading the revision register to figure this one
> out without having to add a new DT attribute ?
> 
I did a quick patch to read the Module revision register:
http://slexy.org/view/s21TKvlWlR

sdp2430: Revision: 1.2, Spec: 0.0, normal interrupt

OMAP3430-ldp: (ES2.1): Revision: 2.6, Spec: 0.0, normal interrupt
SDP3430:(ES3.0) Revision: 2.6, Spec: 0.0, normal interrupt
AM3517-evm: (ES1.1): Revision: 2.6, Spec: 0.0, normal interrupt
AM3517-crane:(ES1.1): Revision: 2.6, Spec: 0.0, normal interrupt

AM37x-evm: (ES1.2) Revision: 2.6, Spec: 0.0, normal interrupt
OMAP3630-beag-xm (ES1.2): Revision: 2.6, Spec: 0.0, normal interrupt

am335x-evm:(ES1.0): Revision: 3.1, Spec: 0.1, normal interrupt
am335x-sk: (ES2.1): Revision: 3.1, Spec: 0.1, normal interrupt
am335x-beaglebone-black:(ES2.0): Revision: 3.1, Spec: 0.1, normal
interrupt

sdp4430.txt: (ES2.2): Revision: 3.1, Spec: 0.1, normal interrupt

OMAP4460-panda-es (ES1.1): Revision: 3.1, Spec: 0.1, normal interrupt

OMAP5uevm:(ES2.0): Revision: 3.3, Spec: 0.2, normal interrupt
dra7-evm (es1.1): Revision: 3.3, Spec: 0.2, normal interrupt

OMAP3430-ldp seems to be the only one impacted with module revision
2.6 -> so using revision information is not really helpful here. Hence
the usage of a flag in dt attribute to indicate hardware impacted by
erratum.

-- 
Regards,
Nishanth Menon