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> >>>> --- >>>> drivers/mmc/host/Kconfig | 2 + >>>> drivers/mmc/host/sdhci-omap.c | 90 ++++++++++++++++++++++++++++++++++- >>>> 2 files changed, 91 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig >>>> index 1b58739d9744..6d3553f06f27 100644 >>>> --- a/drivers/mmc/host/Kconfig >>>> +++ b/drivers/mmc/host/Kconfig >>>> @@ -969,6 +969,8 @@ config MMC_SDHCI_XENON >>>> config MMC_SDHCI_OMAP >>>> tristate "TI SDHCI Controller Support" >>>> depends on MMC_SDHCI_PLTFM && OF >>>> + select THERMAL >>>> + select TI_SOC_THERMAL >>>> help >>>> This selects the Secure Digital Host Controller Interface (SDHCI) >>>> support present in TI's DRA7 SOCs. The controller supports >>>> diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c >>>> index b3cb39d0db6f..9ccce7ef3a60 100644 >>>> --- a/drivers/mmc/host/sdhci-omap.c >>>> +++ b/drivers/mmc/host/sdhci-omap.c >>>> @@ -27,6 +27,7 @@ >>>> #include <linux/regulator/consumer.h> >>>> #include <linux/pinctrl/consumer.h> >>>> #include <linux/sys_soc.h> >>>> +#include <linux/thermal.h> >>>> >>>> #include "sdhci-pltfm.h" >>>> >>>> @@ -286,14 +287,18 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) >>>> struct sdhci_host *host = mmc_priv(mmc); >>>> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >>>> struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); >>>> + struct thermal_zone_device *thermal_dev; >>>> struct device *dev = omap_host->dev; >>>> struct mmc_ios *ios = &mmc->ios; >>>> u32 start_window = 0, max_window = 0; >>>> + bool single_point_failure = false; >>>> u8 cur_match, prev_match = 0; >>>> u32 length = 0, max_len = 0; >>>> u32 phase_delay = 0; >>>> + int temperature; >>>> int ret = 0; >>>> u32 reg; >>>> + int i; >>>> >>>> /* clock tuning is not needed for upto 52MHz */ >>>> if (ios->clock <= 52000000) >>>> @@ -303,6 +308,16 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) >>>> if (ios->timing == MMC_TIMING_UHS_SDR50 && !(reg & CAPA2_TSDR50)) >>>> return 0; >>>> >>>> + thermal_dev = thermal_zone_get_zone_by_name("cpu_thermal"); >>>> + if (IS_ERR(thermal_dev)) { >>>> + dev_err(dev, "Unable to get thermal zone for tuning\n"); >>>> + return PTR_ERR(thermal_dev); >>>> + } >>> >>> 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. Thanks, Faiz
