mmc: sdhci-msm: Actually set the actual clock

Browse source

The MSM SDHCI driver always set the "actual_clock" field to 0.  It had
a comment about it not being needed because we weren't using the
standard SDHCI divider mechanism and we'd just fallback to
"host->clock".  However, it's still better to provide the actual
clock.  Why?

1. It will make timeout calculations slightly better.  On one system I
   have, the eMMC requets 200 MHz (for HS400-ES) but actually gets 192
   MHz.  These are close, but why not get the more accurate one.

2. If things are seriously off in the clock driver and it's missing
   rates or picking the wrong rate (maybe it's rounding up instead of
   down), this will make it much more obvious what's going on.

NOTE: we have to be a little careful here because the "actual_clock"
field shouldn't include the multiplier that sdhci-msm needs
internally.

Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Link: https://lore.kernel.org/r/20201214092048.v5.2.I7564620993acd4baa63fa0e3925ca879a86d3ee3@changeid
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

...

This commit is contained in:

Douglas Anderson 2020-12-14 09:21:15 -08:00 • committed by Ulf Hansson

parent a8cd989e1a

commit f16c8fd444

1 changed files with 16 additions and 19 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

35

drivers/mmc/host/sdhci-msm.c

View file