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? Thanks, Faiz
