On Tue, Jan 24, 2017 at 09:18:46AM +0100, Ulf Hansson wrote:

On 16 January 2017 at 17:56, Maxime Ripard
[off-list ref] wrote:

quoted

The A64 MMC controllers need DATA0 to be masked while updating the clock,
otherwise any subsequent command will result in a timeout.

Could you elaborate on what mask DATA0 really means? I don't follow.

To be honest, I don't really know :)

This is how it's called both in the vendor tree and the datasheet. I
*think* it might be the first data line on the bus, but I'm not sure
exactly why that would cause any issue when updating the clock.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com