[U-Boot] [PATCH 2/2] EXYNOS: SPI: Support SPI_PREAMBLE mode

[Simon Glass]

HI Vadim,

On Thu, May 2, 2013 at 11:12 PM, Vadim Bendebury <vbendeb at chromium.org> wrote:
> [the original patch removed, re-sending from a registered address]
>
> So, I spent some more time debugging a system which requires this
> patch: a system, where on a SPI interface a response to a command
> could come way later then the command data transmission completes.
>
> The original patch was trying to address many corner cases, but come
> to think of it, in this situation the slave does not care about extra
> data sent on the transmit interface, as otherwise there is no clock
> and no data could be transferred from the slave.
>
> Then, for this SPI interface we do not need to set the counter of
> clocks, and do not need to keep adding more clocks if the data has not
> been received yet, the clocks could be just free running. And then the
> patch becomes much simpler, what do you think:

Does this deal with the performance problems that the old driver code
had? There were a number of other patches sent upstream by Rajeshwari
also. I wonder if it might be easier to do your improvement as a
separate patch on top of those instead. Then it can be considered on
its merits.

Regards,
Simon