On Thu, 2020-12-10 at 15:03 +0200, Grygorii Strashko wrote: > > On 10/12/2020 03:56, Qii Wang wrote: > > On Mon, 2020-12-07 at 18:35 +0200, Grygorii Strashko wrote: > >> > >>> > >>> On Thu, 2020-12-03 at 10:01 +0200, Grygorii Strashko wrote: > >>>> > >>>> On 03/12/2020 03:25, Qii Wang wrote: > >>>>> On Wed, 2020-12-02 at 16:35 +0100, Wolfram Sang wrote: > >>>>>> Hi, > >>>>>> > >>>>>>> Some i2c device driver indirectly uses I2C driver when it is now > >>>>>>> being suspended. The i2c devices driver is suspended during the > >>>>>>> NOIRQ phase and this cannot be changed due to other dependencies. > >>>>>>> Therefore, we also need to move the suspend handling for the I2C > >>>>>>> controller driver to the NOIRQ phase as well. > >>>>>>> > >>>>>>> Signed-off-by: Qii Wang <qii.wang@xxxxxxxxxxxx> > >>>>>> > >>>>>> Is this a bugfix and should go into 5.10? Or can it wait for 5.11? > >>>>>> > >>>>> > >>>>> Yes, Can you help to apply it into 5.10? Thanks > >>>> > >>>> To be honest if you still do have any i2c device which accessing i2c buss after _noirq > >>>> stage and your driver does not implement .master_xfer_atomic() - you definitely have a bigger problem. > >>>> So adding IRQF_NO_SUSPEND sound like a hack and probably works just by luck. > >>>> > >>> > >>> At present, it is only a problem caused by missing interrupts, > >>> and .master_xfer_atomic() just a implement in polling mode. Why not set > >>> the interrupt to a state that can always be triggered? > >>> > >>> > >> > >> Because you must not use any IRQ driven operations after _noirq suspend state as it might (and most probably will) > >> cause unpredictable behavior later in suspend_enter(): > >> > >> arch_suspend_disable_irqs(); > >> BUG_ON(!irqs_disabled()); > >> ^after this point any IRQ driven I2C transfer will cause IRQ to be re-enabled > >> > >> if you need turn off device from platform callbacks - .master_xfer_atomic() has to be implemented and used. > >> > > Maybe my comment is a bit disturbing.Our purpose is not to call i2c and > > use interrupts after _noirq pauses.So We use > > i2c_mark_adapter_suspended&i2c_mark_adapter_resumed to block these i2c > > transfers, There will not have any IRQ driven I2C transfer after this > > point: > > arch_suspend_disable_irqs(); > > BUG_ON(!irqs_disabled()); > > But some device driver will do i2c transfer after > > dpm_noirq_resume_devices in dpm_resume_noirq(PMSG_RESUME) when our > > driver irq hasn't resume. > > void dpm_resume_noirq(pm_message_t state) > > { > > dpm_noirq_resume_devices(state); > > Just to clarify. You have resume sequence in dpm_noirq_resume_devices > dpm_noirq_resume_devices -> resume I2C -> resume some device -> do i2c transfer after? > Yes. > Is "some device" in Kernel mainline? > The problematic device driver is drivers/regulator/da9211-regulator.c in Kernel mainline. > > resume_device_irqs(); > > device_wakeup_disarm_wake_irqs(); > > cpuidle_resume(); > > } > > .master_xfer_atomic() seems to be invalid for this question at this > > time? > > >