Messages in this thread | | | Date | Thu, 21 Oct 2021 09:44:56 +0200 | From | Oleksij Rempel <> | Subject | Re: [PATCH v2] thermal: imx: implement runtime PM support |
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On Thu, Oct 21, 2021 at 09:41:35AM +0200, Daniel Lezcano wrote: > On 21/10/2021 09:20, Oleksij Rempel wrote: > > Hi Petr, > > > > On Wed, Oct 20, 2021 at 05:53:03PM +0200, Petr Benes wrote: > >> On Wed, 20 Oct 2021 at 07:05, Oleksij Rempel <o.rempel@pengutronix.de> wrote: > >>> > >>> Hi Petr and Michal, > >>> > >>> I forgot to add you for v2 in CC. Please test/review this version. > >> > >> Hi Oleksij, > >> > >> It works good. with PM as well as without PM. The only minor issue I found is, > >> that the first temperature reading (when the driver probes) fails. That is > >> (val & soc_data->temp_valid_mask) == 0) holds true. How does > >> pm_runtime_resume_and_get() behave in imx_thermal_probe()? > >> Does it go through imx_thermal_runtime_resume() with usleep_range()? > > > > On the first temperature reading, the PM and part of HW is not > > initialized. Current probe sequence is racy and has at least following > > issues: > > - thermal_zone_device_register is executed before HW init was completed. > > It kind of worked before my patch, becaus part of reinit was done by > > temperature init. It worked, since the irq_enabled flag was not set, > > but potentially would run enable_irq() two times if device is > > overheated on probe. > > - the imx_thermal core is potentially disable after first race > > condition: > > CPU0 CPU1 > > thermal_zone_device_register() > > imx_get_temp() > > irq_enabled == false > > power_up > > read_temp > > power_up > > power_down > > irq_enabled = true; > > > > ... at this point imx_thermal is powered down for some amount of time, > > over temperature IRQ will not be triggered for some amount of time. > > > > - if some part after thermal_zone_device_register() would fail or > > deferred, the worker polling temperature will run in to NULL pointer. > > This issue already happened... > > > > After migrating to runtime PM, one of issues started to be visible even > > on normal conditions. > > I'll send one more patch with reworking probe sequence. > > Are you planning to send a v3 with this patch? Or a separate patch?
I'm OK with both variants. What do you prefer?
I'll do i on top of PM patch to reduce refactoring overhead, if you OK about it.
Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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