Hi,

On Thu, Nov 01, 2012 at 01:21:36AM +0530, Venkatraman S wrote:

On Wed, Oct 31, 2012 at 5:56 PM, Felipe Balbi [off-list ref] wrote:

quoted

Hi,

On Wed, Oct 31, 2012 at 05:27:36PM +0530, Hebbar, Gururaja wrote:

quoted

HSMMC IP on AM33xx need a special setting to handle High-speed cards.
Other platforms like TI81xx, OMAP4 may need this as-well. This depends
on the HSMMC IP timing closure done for the high speed cards.

From AM335x TRM (SPRUH73F - 18.3.12 Output Signals Generation)

The MMC/SD/SDIO output signals can be driven on either falling edge or
rising edge depending on the SD_HCTL[2] HSPE bit. This feature allows
to reach better timing performance, and thus to increase data transfer
frequency.

There are few pre-requisites for enabling the HSPE bit
- Controller should support High-Speed-Enable Bit and
- Controller should not be using DDR Mode and
- Controller should advertise that it supports High Speed in
  capabilities register and
- MMC/SD clock coming out of controller > 25MHz

Note:
The implementation reuses the output of calc_divisor() so as to reduce
code addition.

Signed-off-by: Hebbar, Gururaja <redacted>

this looks good to my eyes, hopefully I haven't missed anything:

Reviewed-by: Felipe Balbi <redacted>

Except for the excessively verbose comments which are just duplicating the code,
<Quote>

quoted

quoted

+      * Enable High-Speed Support
+      * Pre-Requisites
+      *      - Controller should support High-Speed-Enable Bit
+      *      - Controller should not be using DDR Mode
+      *      - Controller should advertise that it supports High Speed
+      *        in capabilities register
+      *      - MMC/SD clock coming out of controller > 25MHz
+      */

</Quote>

I'm ok with this patch as well. I'm putting a few patches under test
including this one,
and will send it to Chris as part of that series.
I'll strip out the above mentioned comments, unless there are any
objections.

please don't. Detailing the pre-requisites for getting HSP mode working
isn't bad at all. Should someone decide to change the behavior and ends
up breaking it, the comment will help putting things back together.

my 2 cents, you've got the final decision though.

-- 
balbi