Re: [PATCH V2 01/12] spi/mxs: Always set LOCK_CS

[Marek Vasut <marex@denx.de>]

Hello Trent,

> There are two bits which control the CS line in the CTRL0 register:
> LOCK_CS and IGNORE_CRC.  The latter would be better named DEASSERT_CS
> in SPI mode.
> 
> LOCK_CS keeps CS asserted though the entire transfer.  This should
> always be set.  The DMA code will always set it, explicitly on the
> first segment of the first transfer, and then implicitly on all the
> rest by never clearing the bit from the value read from the ctrl0
> register.
> 
> The only reason to not set LOCK_CS would be to attempt an altered
> protocol where CS pulses between each word.  Though don't get your
> hopes up if you want to do this, as the hardware doesn't appear to do
> this in any sane manner.
> 
> The code can be simplified by just setting LOCK_CS once and then not
> needing to deal with it in the PIO and DMA transfer functions.
> 
> Signed-off-by: Trent Piepho <tpiepho@gmail.com>
> Cc: Marek Vasut <marex@denx.de>
> Cc: Fabio Estevam <fabio.estevam@freescale.com>
> Cc: Shawn Guo <shawn.guo@linaro.org>

Will we see a V3 of this stuff? I don't want to see this lost.

Best regards,
Marek Vasut