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. Thanks, Faiz
