ACPI / LPSS: Save/restore LPSS private registers also on Lynxpoint
authorJarkko Nikula <jarkko.nikula@linux.intel.com>
Thu, 22 Aug 2019 08:32:00 +0000 (11:32 +0300)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 23 Aug 2019 10:53:14 +0000 (12:53 +0200)
commit57b3006492a4c11b2d4a772b5b2905d544a32037
tree5e0861694c827119b1f9c1624ba707d43d5850b5
parentd1abaeb3be7b5fa6d7a1fbbd2e14e3310005c4c1
ACPI / LPSS: Save/restore LPSS private registers also on Lynxpoint

My assumption in commit b53548f9d9e4 ("spi: pxa2xx: Remove LPSS private
register restoring during resume") that Intel Lynxpoint and compatible
based chipsets may not need LPSS private registers saving and restoring
over suspend/resume cycle turned out to be false on Intel Broadwell.

Curtis Malainey sent a patch bringing above change back and reported the
LPSS SPI Chip Select control was lost over suspend/resume cycle on
Broadwell machine.

Instead of reverting above commit lets add LPSS private register
saving/restoring also for all LPSS SPI, I2C and UART controllers on
Lynxpoint and compatible chipset to make sure context is not lost in
case nothing else preserves it like firmware or if LPSS is always on.

Fixes: b53548f9d9e4 ("spi: pxa2xx: Remove LPSS private register restoring during resume")
Reported-by: Curtis Malainey <cujomalainey@chromium.org>
Tested-by: Curtis Malainey <cujomalainey@chromium.org>
Cc: 5.0+ <stable@vger.kernel.org> # 5.0+
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/acpi/acpi_lpss.c