linux/drivers/i2c
Rafael J. Wysocki 5415277283 PM: i2c-designware-platdrv: Suspend/resume at the late/early stages
As reported by Rajat Jain, there are problems when ACPI operation
region handlers or similar, called at the ->resume_early() time, for
I2C client devices try to access an I2C controller that has already
been suspended at that point.  To avoid that, move the suspend/resume
of i2c-designware-platdrv to the late/early stages, respectively.

While at it, avoid resuming the device from runtime suspend in the
driver's ->suspend callback which isn't particularly nice.  [A better
approach would be to make the driver track the PM state of the device
so that it doesn't need to resume it in ->suspend, so implement it.]

First, drop dw_i2c_plat_suspend() added by commit a23318feef (i2c:
designware: Fix system suspend) and rename dw_i2c_plat_runtime_suspend()
back to dw_i2c_plat_suspend().

Second, point the driver's ->late_suspend and ->early_resume
callbacks, rather than its ->suspend and ->resume callbacks,
to dw_i2c_plat_suspend() and dw_i2c_plat_resume(), respectively,
so that they are not executed in parallel with each other, for
example if runtime resume of the device takes place during system
suspend.

Finally, add "suspended" and "skip_resume" flags to struct dw_i2c_dev
and make dw_i2c_plat_suspend() and dw_i2c_plat_resume() use them to
avoid suspending or resuming the device twice in a row and to avoid
resuming a previously runtime-suspended device during system resume.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Johannes Stezenbach <js@sig21.net>
Tested-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-05 13:00:29 +02:00
..
algos i2c: algo-bit: add support for I2C_M_STOP 2017-06-23 20:45:43 +02:00
busses PM: i2c-designware-platdrv: Suspend/resume at the late/early stages 2017-10-05 13:00:29 +02:00
muxes Merge branch 'i2c/for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2017-09-09 14:18:40 -07:00
i2c-boardinfo.c i2c: allow attaching IRQ resources to i2c_board_info 2017-04-01 09:36:19 -07:00
i2c-core-acpi.c i2c: core: Allow empty id_table in ACPI case as well 2017-07-31 15:50:33 +02:00
i2c-core-base.c i2c: core: Make comment about I2C table requirement to reflect the code 2017-08-14 21:33:46 +02:00
i2c-core-of.c i2c: Convert to using %pOF instead of full_name 2017-07-31 17:19:35 +02:00
i2c-core-slave.c i2c: break out slave support into separate file 2017-05-31 21:01:03 +02:00
i2c-core-smbus.c i2c: break out smbus support into separate file 2017-05-31 21:01:03 +02:00
i2c-core.h i2c: core: Allow empty id_table in ACPI case as well 2017-07-31 15:50:33 +02:00
i2c-dev.c i2c: fix kernel memory disclosure in dev interface 2017-01-12 20:06:10 +01:00
i2c-mux.c i2c: mux: only print failure message on error 2017-05-15 18:49:11 +02:00
i2c-slave-eeprom.c i2c: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
i2c-smbus.c i2c: use an IRQ to report Host Notify events, not alert 2016-11-24 16:22:06 +01:00
i2c-stub.c i2c: stub: fix build warning regression 2017-06-15 23:22:11 +02:00
Kconfig Merge branch 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2016-12-15 12:56:35 -08:00
Makefile i2c: break out ACPI support into separate file 2017-05-31 21:01:04 +02:00