mmc: sdhci: Fix voltage switch delay
authorAdrian Hunter <adrian.hunter@intel.com>
Mon, 28 Nov 2022 13:32:56 +0000 (15:32 +0200)
committerUlf Hansson <ulf.hansson@linaro.org>
Tue, 29 Nov 2022 12:42:42 +0000 (13:42 +0100)
commitc981cdfb9925f64a364f13c2b4f98f877308a408
tree6a40d833d1581fca8725b5e840ecd5f72b3dba7c
parentc61bfb1cb63ddab52b31cf5f1924688917e61fad
mmc: sdhci: Fix voltage switch delay

Commit 20b92a30b561 ("mmc: sdhci: update signal voltage switch code")
removed voltage switch delays from sdhci because mmc core had been
enhanced to support them. However that assumed that sdhci_set_ios()
did a single clock change, which it did not, and so the delays in mmc
core, which should have come after the first clock change, were not
effective.

Fix by avoiding re-configuring UHS and preset settings when the clock
is turning on and the settings have not changed. That then also avoids
the associated clock changes, so that then sdhci_set_ios() does a single
clock change when voltage switching, and the mmc core delays become
effective.

To do that has meant keeping track of driver strength (host->drv_type),
and cases of reinitialization (host->reinit_uhs).

Note also, the 'turning_on_clk' restriction should not be necessary
but is done to minimize the impact of the change on stable kernels.

Fixes: 20b92a30b561 ("mmc: sdhci: update signal voltage switch code")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20221128133259.38305-2-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
drivers/mmc/host/sdhci.c
drivers/mmc/host/sdhci.h