Messages in this thread | | | Date | Fri, 9 Dec 2022 13:36:07 +0000 | Subject | Re: [PATCH] i2c: designware: Fix unbalanced suspended flag | From | Richard Fitzgerald <> |
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On 9/12/22 12:15, Hans de Goede wrote: > Hi Richard, > > On 12/9/22 12:40, Richard Fitzgerald wrote: >> Ensure that i2c_mark_adapter_suspended() is always balanced by a call to >> i2c_mark_adapter_resumed().
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> > It is not entirely clear to me where the unbalance you claim to see comes > from? When runtime-suspended SMART_SUSPEND should keep it suspended at which point > the system suspend callback will never run ? > > Are you sure that you are not maybe seeing a suspend/resume ordering issue? > > Did you add printk messages to the suspend/resume callbacks of > i2c-designware-platdrv.c which show the system suspend callback > being called but not the system resume one ? >
With messages in strategic places.
[ 169.607358] i2c_designware i2c_designware.2: PM: dev_pm_skip_suspend: SMART_SUSPEND=0 pm_runtime_status_suspended=1 [ 169.607361] i2c_designware i2c_designware.2: PM: __device_suspend_late: dev_pm_skip_suspend:false [ 169.607364] i2c_designware i2c_designware.2: dw_i2c_plat_suspend ... [ 169.702511] i2c_designware i2c_designware.2: PM: dev_pm_skip_resume: 1 because !power.must_resume [ 169.706241] i2c_designware i2c_designware.2: PM: dev_pm_skip_resume: 1 because !power.must_resume [ 169.706244] i2c_designware i2c_designware.2: PM: device_resume_early: dev_pm_skip_resume:true ... [ 175.254832] i2c i2c-2: Transfer while suspended
(Just to prove my logging isn't lying, for i2c3 it reports SMART_SUSPEND=1)
So it can skip the resume even if it didn't skip the suspend. The SMART_SUSPEND flag is not set on i2c2 and the driver core can skip resume even if it didn't skip suspend.
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