Hi, On 10/12/18 10:26 PM, Ulf Hansson wrote: > On Mon, 10 Dec 2018 at 17:43, Faiz Abbas <faiz_abbas@xxxxxx> wrote: >> >> Hi, >> >> On 10/12/18 8:55 PM, Ulf Hansson wrote: >>> On Mon, 10 Dec 2018 at 15:04, Faiz Abbas <faiz_abbas@xxxxxx> wrote: >>>> >>>> Hi, >>>> >>>> On 10/12/18 7:15 PM, Ulf Hansson wrote: >>>>> On Mon, 10 Dec 2018 at 14:23, Faiz Abbas <faiz_abbas@xxxxxx> wrote: >>>>>> >>>>>> Hi Uffe, >>>>>> >>>>>> On 05/12/18 7:20 PM, Ulf Hansson wrote: >>>>>>> On Fri, 30 Nov 2018 at 06:53, Faiz Abbas <faiz_abbas@xxxxxx> wrote: >>>>>>>> >>>>>>>> Hi Kishon, >>>>>>>> >>>>>>>> On 30/11/18 10:10 AM, Kishon Vijay Abraham I wrote: >>>>>>>>> Hi Faiz, >>>>>>>>> >>>>>>>>> On 30/11/18 12:35 AM, Faiz Abbas wrote: >>>>>>>>>> Errata i929 in certain OMAP5/DRA7XX/AM57XX silicon revisions >>>>>>>>>> (SPRZ426D - November 2014 - Revised February 2018 [1]) mentions >>>>>>>>>> unexpected tuning pattern errors. A small failure band may be present >>>>>>>>>> in the tuning range which may be missed by the current algorithm. >>>>>>>>>> Furthermore, the failure bands vary with temperature leading to >>>>>>>>>> different optimum tuning values for different temperatures. >>>>>>>>>> >>>>>>>>>> As suggested in the related Application Report (SPRACA9B - October 2017 >>>>>>>>>> - Revised July 2018 [2]), tuning should be done in two stages. >>>>>>>>>> In stage 1, assign the optimum ratio in the maximum pass window for the >>>>>>>>>> current temperature. In stage 2, if the chosen value is close to the >>>>>>>>>> small failure band, move away from it in the appropriate direction. >>>>>>>>>> >>>>>>>>>> References: >>>>>>>>>> [1] http://www.ti.com/lit/pdf/sprz426 >>>>>>>>>> [2] http://www.ti.com/lit/pdf/SPRACA9 >>>>>>>>>> >>>>>>>>>> Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx> >>>>>>>>>> --- >>>> ... >>>>>>>>> >>>>>>>>> Can't we get thermal zone once during probe? >>>>>>>>> >>>>>>>> >>>>>>>> Tuning is also (ideally) supposed to happen only once per enumeration. >>>>>>>> Also it doesn't make sense to get a thermal zone for lower speed systems >>>>>>>> that won't do tuning. >>>>>>> >>>>>>> Currently sdhci-omap calls pm_runtime_get_sync() during probe, and >>>>>>> then keeps the host device runtime resumed until ->remove() is called >>>>>>> on it. I assume you are going to change that, at some point!? >>>>>>> >>>>>>> In other words, what will happen to the host device when it becomes >>>>>>> runtime suspended? Is re-tuning needed when it gets runtime resumed, >>>>>>> which is the case for many other sdhci variants? >>>>>> >>>>>> There are no plans to support runtime_suspend()/resume() any time in the >>>>>> near future. If its ok with you, I would like to get this patch in >>>>>> without any changes. We can change it in case a need for >>>>>> runtime_suspend()/_resume() does arise. >>>>> >>>>> Right, I am okay with that. Due to recent changes to sdhci-omap >>>>> $subject patch doesn't apply, can you please rebase!? >>>>> >>>>> Additionally, I realized that we should fold in patch updating the DT >>>>> doc for sdhci-omap, adding the property for the thermal zone. I >>>>> regards to that, I am wondering if "cpu_thermal", is really the >>>>> correct name of the zone. The point is, I am guessing the zone could >>>>> change along with the SoCs/platforms. >>>>> >>>> >>>> As you have probably noticed, we are introducing a new driver >>>> (sdhci_am654) for newer platforms. I don't foresee using sdhci-omap >>>> driver with any other platforms. In case we do use it, we can add the dt >>>> property at that point of time and default to "cpu_thermal" to maintain >>>> dt compatibility. >>>> >>>> Will rebase and send v2 if you are ok with above. >>> >>> I see, but you still need to update the DT doc for sdhci-omap. >>> >> >> I didn't get you. There are no changes in dt. What changes should I >> document? > > Well, you are fetching a thermal zone using a specific name. It's > quite similar to how we document other resources (pinctrls for > example) that sdhci omap depends on, so that needs to be document too. > Ok. Will add a note for "cpu_thermal" in the documentation. Thanks, Faiz
