| Message ID | 20240102-j7200-pcie-s2r-v3-4-5c2e4a3fac1f@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add suspend to ram support for PCIe on J7200 | expand |
On Thu, Feb 15, 2024 at 04:17:49PM +0100, Thomas Richard wrote: > A device may need the controller up during suspend_noirq() or > resume_noirq(). > But if the controller is autosuspended, there is no way to wakeup it during > suspend_noirq() or resume_noirq() because runtime pm is disabled at this > time. > > The suspend() callback wakes up the controller, so it is available until > its suspend_noirq() callback (pm_runtime_force_suspend()). > During the resume, it's restored by resume_noirq() callback > (pm_runtime_force_resume()). Then resume() callback enables autosuspend. > > So the controller is up during a little time slot in suspend and resume > sequences even if it's not used. ... > + /* > + * If the controller is autosuspended, there is no way to wakeup it once > + * runtime pm is disabled (in suspend_late()). > + * But a device may need the controller up during suspend_noirq() or > + * resume_noirq(). > + * Wakeup the controller while runtime pm is enabled, so it is available until > + * its suspend_noirq(), and from resume_noirq(). > + */ It's a bit random line lengths... Can you repack this to be more condensed?
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 42165ef57946..c11deb285114 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -1575,9 +1575,31 @@ static int __maybe_unused omap_i2c_runtime_resume(struct device *dev) return 0; } +static int omap_i2c_suspend(struct device *dev) +{ + /* + * If the controller is autosuspended, there is no way to wakeup it once + * runtime pm is disabled (in suspend_late()). + * But a device may need the controller up during suspend_noirq() or + * resume_noirq(). + * Wakeup the controller while runtime pm is enabled, so it is available until + * its suspend_noirq(), and from resume_noirq(). + */ + return pm_runtime_resume_and_get(dev); +} + +static int omap_i2c_resume(struct device *dev) +{ + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + + return 0; +} + static const struct dev_pm_ops omap_i2c_pm_ops = { SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) + SET_SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume) SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend, omap_i2c_runtime_resume, NULL) };
A device may need the controller up during suspend_noirq() or resume_noirq(). But if the controller is autosuspended, there is no way to wakeup it during suspend_noirq() or resume_noirq() because runtime pm is disabled at this time. The suspend() callback wakes up the controller, so it is available until its suspend_noirq() callback (pm_runtime_force_suspend()). During the resume, it's restored by resume_noirq() callback (pm_runtime_force_resume()). Then resume() callback enables autosuspend. So the controller is up during a little time slot in suspend and resume sequences even if it's not used. Signed-off-by: Thomas Richard <thomas.richard@bootlin.com> --- drivers/i2c/busses/i2c-omap.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)