Messages in this thread | | | From | Petr Benes <> | Date | Mon, 15 Nov 2021 16:02:07 +0100 | Subject | Re: [PATCH v2] thermal: imx: implement runtime PM support |
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Hi Oleksij,
On Thu, 11 Nov 2021 at 10:16, Oleksij Rempel <o.rempel@pengutronix.de> wrote: > > On Wed, Nov 10, 2021 at 11:07:31AM +0100, Michal Vokáč wrote: > > On 25. 10. 21 13:06, Petr Benes wrote: > > > Hi Oleksij, > > > > > > On Thu, 21 Oct 2021 at 19:21, Oleksij Rempel <o.rempel@pengutronix.de> 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()? > > > > > > > > How exactly did you reproduce it? Even more or less understanding how > > > > > > I just placed my debug print into get_temp() > > > > > > if ((val & soc_data->temp_valid_mask) == 0) { > > > dev_dbg(&tz->device, "temp measurement never finished\n"); > > > printk("Wrong temperature reading!!!!!!\n"); > > > return -EAGAIN; > > > } > > > > > > > this can potentially happen, i never had this issue on my HW. Is it something > > > > HW specific? > > > > > > IMHO it is just product of the following sequence: > > > > > > pm_runtime_set_active(&pdev->dev); > > > pm_runtime_enable(data->dev); > > > pm_runtime_resume_and_get(data->dev); > > > thermal_zone_device_enable(data->tz); > > > > > > With assumption imx_thermal_runtime_resume() didn't run, > > > hence the sensor didn't get enough time to come up. > > > > > > I didn't have time to spend it on and you have better knowledge of the > > > area. If it is not that straightforward I can try to diagnose it better. > > > > > Hi Oleksij, > > Did you manage to further debug and reproduce this problem? > > Do you plan to send the v3? > > > > Regarding your question about the HW - this problem occured once we > > upgraded the SoC on our SBC from i.MX6DL to i.MX6Q/QP. With the DualLite > > we never had this problem but the Quad is getting hot quite fast. > > We have pretty limited cooling options so the core is operated at its > > upper temperature limits when fully loaded. > > Hi Michal, > > Sorry, I was busy and lost this topic from my radar. I was not able to > reproduce it on my i.MX6Q and i.MX6QP died after other thermal voltage > experiments. Please, if you able to reproduce it, try to investigate > what is wrong, for example increasing wakeup time and/or and tracing > sleap/wake/get sequences.
Seems it is just as easy as calling usleep_range(20, 50) when you switch on the sensor and enable temperature measurement in imx_thermal_probe(). So, we are sure the sensor is configured and _ready_.
You call pm_runtime_set_active(), pm_runtime_enable(), and pm_runtime_resume_and_get(). The last one doesn't call the resume callback (which correctly handles waiting for the sensor) as the device is already active.
On some SoCs the timing leads to a failure of the temperature readout in thermal_zone_device_enable() which follows. I've seen it on i.MX6DL, but cannot reproduce it on i.MX6QP for example.
Regards, Petr
> > 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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