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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-09-25 02:30:51 +0300 |
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committer | Wolfram Sang <wsa@the-dreams.de> | 2017-10-05 14:00:29 +0300 |
commit | 541527728341b4bb9a5e3428b0eec450f1b3d8d5 (patch) | |
tree | e6d10b5567973cdee07209939d3f2cbf298e01a3 /drivers/i2c/busses/i2c-designware-platdrv.c | |
parent | e00952c7904a34359872813c3b072eba55065090 (diff) | |
download | linux-541527728341b4bb9a5e3428b0eec450f1b3d8d5.tar.xz |
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 a23318feeff6 (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>
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-platdrv.c')
-rw-r--r-- | drivers/i2c/busses/i2c-designware-platdrv.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 532e5a6e8512..16c027b62a20 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -447,13 +447,20 @@ static void dw_i2c_plat_complete(struct device *dev) #endif #ifdef CONFIG_PM -static int dw_i2c_plat_runtime_suspend(struct device *dev) +static int dw_i2c_plat_suspend(struct device *dev) { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + if (i_dev->suspended) { + i_dev->skip_resume = true; + return 0; + } + i_dev->disable(i_dev); i2c_dw_plat_prepare_clk(i_dev, false); + i_dev->suspended = true; + return 0; } @@ -461,27 +468,27 @@ static int dw_i2c_plat_resume(struct device *dev) { struct dw_i2c_dev *i_dev = dev_get_drvdata(dev); + if (!i_dev->suspended) + return 0; + + if (i_dev->skip_resume) { + i_dev->skip_resume = false; + return 0; + } + i2c_dw_plat_prepare_clk(i_dev, true); i_dev->init(i_dev); - return 0; -} + i_dev->suspended = false; -#ifdef CONFIG_PM_SLEEP -static int dw_i2c_plat_suspend(struct device *dev) -{ - pm_runtime_resume(dev); - return dw_i2c_plat_runtime_suspend(dev); + return 0; } -#endif static const struct dev_pm_ops dw_i2c_dev_pm_ops = { .prepare = dw_i2c_plat_prepare, .complete = dw_i2c_plat_complete, - SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) - SET_RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend, - dw_i2c_plat_resume, - NULL) + SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) + SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) }; #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) |