Re: [PATCH] soc: qcom-geni-se: Don't use relaxed writes when writing commands

[Stephen Boyd]

Quoting Douglas Anderson (2020-07-22 15:01:20)
> Writing the command is the final step in kicking off a transfer.
> Let's use writel() to ensure that any other memory accesses are done
> before the command kicks off.  It's expected that this is mostly
> relevant if we're in DMA mode but since it doesn't appear to regress
> performance in a measurable way [1] even in PIO mode and it's easier
> to reason about then let's just always use it.
> 
> NOTE: this patch came about due to code inspection.  No actual
> problems were observed that this patch fixes.
> 
> [1] Tested by timing "flashrom -p ec" on a Chromebook which stresses
> GENI SPI a lot.
> 
> Suggested-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---

Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>