stm32: spi: Fix race condition with the enabled boolean

Sometimes the chipset task is slow enough that we might get messages from
the AP before chipset_in_state(CHIPSET_STATE_ON) is true. This causes us
to leave the spi off after our usual reset after every transaction
(see chrome-os-partner:31390). This would put an end to any EC communications.

Instead of relying on CHIPSET_STATE_ON we could just save the value of
"enabled" before we turn it off, then use that as a condition instead.

There shouldn't be a race condition on "enabled" because the only other place
it gets modified is in the hooks, which can't preempt spi_init
(which usually happens in the host command task).

The only problem is that in case of a sysjump enabled will be 0,
so CHIPSET_STATE_ON was left as a backup to handle that case.
This fixup was squashed from Ied3788f83fef548dff3b01bec93d0e40101ba0f7

TEST=Resume minnie from "echo mem>/sys/power/state" a few times, note ec still works
BUG=chrome-os-partner:39564, chrome-os-partner:39576
BRANCH=veyron

Change-Id: I7c33243faebfd74dc33451024c1d75080babee03
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/267593
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

0 files changed, 0 insertions, 0 deletions