soc: qcom: geni: Optimize/comment select fifo/dma mode
authorDouglas Anderson <dianders@chromium.org>
Tue, 13 Oct 2020 21:25:30 +0000 (14:25 -0700)
committerBjorn Andersson <bjorn.andersson@linaro.org>
Mon, 26 Oct 2020 15:29:19 +0000 (10:29 -0500)
commit80e8eaab5e98fc013fd4afb4aab1fceeb049cbfd
treee8239d6837d30d37160e59220167b96210c0e986
parent9cb4c67d7717135d6f4600a49ab07b470ea4ee2f
soc: qcom: geni: Optimize/comment select fifo/dma mode

The functions geni_se_select_fifo_mode() and
geni_se_select_fifo_mode() are a little funny.  They read/write a
bunch of memory mapped registers even if they don't change or aren't
relevant for the current protocol.  Let's make them a little more
sane.  We'll also add a comment explaining why we don't do some of the
operations for UART.

NOTE: there is no evidence at all that this makes any performance
difference and it fixes no bugs.  However, it seems (to me) like it
makes the functions a little easier to understand.  Decreasing the
amount of times we read/write memory mapped registers is also nice,
even if we are using "relaxed" variants.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20201013142448.v2.3.I646736d3969dc47de8daceb379c6ba85993de9f4@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
drivers/soc/qcom/qcom-geni-se.c