i2c: designware: Never suspend i2c-busses used for accessing the system PMIC
authorHans de Goede <hdegoede@redhat.com>
Mon, 13 Mar 2017 22:25:09 +0000 (23:25 +0100)
committerWolfram Sang <wsa@the-dreams.de>
Wed, 22 Mar 2017 08:53:24 +0000 (09:53 +0100)
commit41c80b8a63bccf9de96698b4eb0916e223fb6e72
treee305de406850c7bb7fccc3286cb773b3df355e4f
parent78c43af2c1d79653e2e6fb9a05c8f3def7c87940
i2c: designware: Never suspend i2c-busses used for accessing the system PMIC

Currently we are already setting a pm_runtime_disabled flag and disabling
runtime-pm for i2c-busses used for accessing the system PMIC on x86.
But this is not enough, there are ACPI opregions which may want to access
the PMIC during late-suspend and early-resume, so we need to completely
disable pm to be safe.

This commit renames the flag from pm_runtime_disabled to pm_disabled and
adds the following new behavior if the flag is set:

1) Call dev_pm_syscore_device(dev, true) which disables normal suspend /
   resume and remove the pm_runtime_disabled check from dw_i2c_plat_resume
   since that will now never get called. This fixes suspend_late handlers
   which use ACPI PMIC opregions causing errors like these:

  PM: Suspending system (freeze)
  PM: suspend of devices complete after 1127.751 msecs
  i2c_designware 808622C1:06: timeout waiting for bus ready
  ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]
  acpi 80860F14:02: Failed to change power state to D3hot
  PM: late suspend of devices failed

2) Set IRQF_NO_SUSPEND irq flag. This fixes resume_early handlers which
   handlers which use ACPI PMIC opregions causing errors like these:

  PM: resume from suspend-to-idle
  i2c_designware 808622C1:06: controller timed out
  ACPI Exception: AE_ERROR, Returned by Handler for [UserDefinedRegion]

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
drivers/i2c/busses/i2c-designware-baytrail.c
drivers/i2c/busses/i2c-designware-core.c
drivers/i2c/busses/i2c-designware-core.h
drivers/i2c/busses/i2c-designware-platdrv.c