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. Kind regards Uffe
