Hi, On 31/03/23 20:01, Ulf Hansson wrote: > On Fri, 31 Mar 2023 at 12:17, Vignesh Raghavendra <vigneshr@xxxxxx> wrote: >> >> From: Aswath Govindraju <a-govindraju@xxxxxx> >> >> Add support for suspend/resume and pm_runtime resume/suspend. >> >> Signed-off-by: Aswath Govindraju <a-govindraju@xxxxxx> >> Signed-off-by: Georgi Vlaev <g-vlaev@xxxxxx> >> Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx> >> --- >> >> Since RFC v2: >> Address all comments around sdhci_am654_remove() >> Set autosuspend_delay to -1 as SDHCI will host rootfs via SD/eMMC and >> autosuspend can cause long latency for user interactive applications > > I am curious about the "long" latency. Do you have some data that you > can share for how long it takes to runtime-resume the device? > As part of wider teting, I discovered that on certain boards (J721e EVM for example), there is a latency of ~500ms for controller to start up (HW limitation around card detect debounce timer [0]). This results in momentary (but noticeable) lag when playing a video for example. [0[ https://elixir.bootlin.com/linux/latest/source/drivers/mmc/host/sdhci_am654.c#L361 > Using -1 as the default value for the autosuspend_delay seems fine to > me, but did you consider using a longer timeout than the common 100ms? > Could that perhaps be a better default option? Its more of the startup delay than how long controller should remain active. So tuning autosuspend_delay does not seem to help. > > Of course, in the end this is a choice of performance in favor of > wasting energy. Yes, this is choice of opt-in vs opt-out. Users can tune the delay via sysfs as needed. I am setting it to -1 to avoid regressing any userspace apps (vs enabling autosuspend and then asking impacted users to set to -1) One solution is to use -1 on platforms where latency is significant based on compatible / SoC detection? Regards Vignesh > > Kind regards > Uffe > >> >> RFC v2: >> https://lore.kernel.org/all/20220408124338.27090-1-a-govindraju@xxxxxx/ >> >> drivers/mmc/host/sdhci_am654.c | 147 +++++++++++++++++++++++++++++---- >> 1 file changed, 131 insertions(+), 16 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c >> index 672d37ea98d0..7cdf0f54e3a5 100644 >> --- a/drivers/mmc/host/sdhci_am654.c >> +++ b/drivers/mmc/host/sdhci_am654.c >> @@ -85,6 +85,7 @@ >> #define DRIVER_STRENGTH_40_OHM 0x4 >> >> #define CLOCK_TOO_SLOW_HZ 50000000 >> +#define SDHCI_AM654_AUTOSUSPEND_DELAY -1 >> >> /* Command Queue Host Controller Interface Base address */ >> #define SDHCI_AM654_CQE_BASE_ADDR 0x200 >> @@ -808,16 +809,10 @@ static int sdhci_am654_probe(struct platform_device *pdev) >> >> pltfm_host->clk = clk_xin; >> >> - /* Clocks are enabled using pm_runtime */ >> - pm_runtime_enable(dev); >> - ret = pm_runtime_resume_and_get(dev); >> - if (ret) >> - goto pm_runtime_disable; >> - >> base = devm_platform_ioremap_resource(pdev, 1); >> if (IS_ERR(base)) { >> ret = PTR_ERR(base); >> - goto pm_runtime_put; >> + goto err_pltfm_free; >> } >> >> sdhci_am654->base = devm_regmap_init_mmio(dev, base, >> @@ -825,31 +820,47 @@ static int sdhci_am654_probe(struct platform_device *pdev) >> if (IS_ERR(sdhci_am654->base)) { >> dev_err(dev, "Failed to initialize regmap\n"); >> ret = PTR_ERR(sdhci_am654->base); >> - goto pm_runtime_put; >> + goto err_pltfm_free; >> } >> >> ret = sdhci_am654_get_of_property(pdev, sdhci_am654); >> if (ret) >> - goto pm_runtime_put; >> + goto err_pltfm_free; >> >> ret = mmc_of_parse(host->mmc); >> if (ret) { >> dev_err_probe(dev, ret, "parsing dt failed\n"); >> - goto pm_runtime_put; >> + goto err_pltfm_free; >> } >> >> host->mmc_host_ops.execute_tuning = sdhci_am654_execute_tuning; >> >> + pm_runtime_get_noresume(dev); >> + ret = pm_runtime_set_active(dev); >> + if (ret) >> + goto pm_put; >> + pm_runtime_enable(dev); >> + ret = clk_prepare_enable(pltfm_host->clk); >> + if (ret) >> + goto pm_disable; >> + >> ret = sdhci_am654_init(host); >> if (ret) >> - goto pm_runtime_put; >> + goto clk_disable; >> >> + /* Setting up autosuspend */ >> + pm_runtime_set_autosuspend_delay(dev, SDHCI_AM654_AUTOSUSPEND_DELAY); >> + pm_runtime_use_autosuspend(dev); >> + pm_runtime_mark_last_busy(dev); >> + pm_runtime_put_autosuspend(dev); >> return 0; >> >> -pm_runtime_put: >> - pm_runtime_put_sync(dev); >> -pm_runtime_disable: >> +clk_disable: >> + clk_disable_unprepare(pltfm_host->clk); >> +pm_disable: >> pm_runtime_disable(dev); >> +pm_put: >> + pm_runtime_put_noidle(dev); >> err_pltfm_free: >> sdhci_pltfm_free(pdev); >> return ret; >> @@ -858,23 +869,127 @@ static int sdhci_am654_probe(struct platform_device *pdev) >> static int sdhci_am654_remove(struct platform_device *pdev) >> { >> struct sdhci_host *host = platform_get_drvdata(pdev); >> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> int ret; >> >> - sdhci_remove_host(host, true); >> - ret = pm_runtime_put_sync(&pdev->dev); >> + ret = pm_runtime_resume_and_get(&pdev->dev); >> if (ret < 0) >> return ret; >> >> + sdhci_remove_host(host, true); >> + clk_disable_unprepare(pltfm_host->clk); >> pm_runtime_disable(&pdev->dev); >> + pm_runtime_put_noidle(&pdev->dev); >> sdhci_pltfm_free(pdev); >> + return 0; >> +} >> + >> +#ifdef CONFIG_PM >> +static int sdhci_am654_restore(struct sdhci_host *host) >> +{ >> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> + struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host); >> + u32 ctl_cfg_2 = 0; >> + u32 val; >> + int ret; >> + >> + if (sdhci_am654->flags & DLL_CALIB) { >> + regmap_read(sdhci_am654->base, PHY_STAT1, &val); >> + if (~val & CALDONE_MASK) { >> + /* Calibrate IO lines */ >> + regmap_update_bits(sdhci_am654->base, PHY_CTRL1, >> + PDB_MASK, PDB_MASK); >> + ret = regmap_read_poll_timeout(sdhci_am654->base, >> + PHY_STAT1, val, >> + val & CALDONE_MASK, >> + 1, 20); >> + if (ret) >> + return ret; >> + } >> + } >> + >> + /* Enable pins by setting IO mux to 0 */ >> + if (sdhci_am654->flags & IOMUX_PRESENT) >> + regmap_update_bits(sdhci_am654->base, PHY_CTRL1, >> + IOMUX_ENABLE_MASK, 0); >> >> + /* Set slot type based on SD or eMMC */ >> + if (host->mmc->caps & MMC_CAP_NONREMOVABLE) >> + ctl_cfg_2 = SLOTTYPE_EMBEDDED; >> + >> + regmap_update_bits(sdhci_am654->base, CTL_CFG_2, SLOTTYPE_MASK, >> + ctl_cfg_2); >> + >> + regmap_read(sdhci_am654->base, CTL_CFG_3, &val); >> + if (~val & TUNINGFORSDR50_MASK) >> + /* Enable tuning for SDR50 */ >> + regmap_update_bits(sdhci_am654->base, CTL_CFG_3, TUNINGFORSDR50_MASK, >> + TUNINGFORSDR50_MASK); >> + >> + return 0; >> +} >> + >> +static int sdhci_am654_runtime_suspend(struct device *dev) >> +{ >> + struct sdhci_host *host = dev_get_drvdata(dev); >> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> + int ret; >> + >> + if (host->tuning_mode != SDHCI_TUNING_MODE_3) >> + mmc_retune_needed(host->mmc); >> + >> + ret = cqhci_suspend(host->mmc); >> + if (ret) >> + return ret; >> + >> + ret = sdhci_runtime_suspend_host(host); >> + if (ret) >> + return ret; >> + >> + /* disable the clock */ >> + clk_disable_unprepare(pltfm_host->clk); >> return 0; >> } >> >> +static int sdhci_am654_runtime_resume(struct device *dev) >> +{ >> + struct sdhci_host *host = dev_get_drvdata(dev); >> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> + int ret; >> + >> + /* Enable the clock */ >> + ret = clk_prepare_enable(pltfm_host->clk); >> + if (ret) >> + return ret; >> + >> + ret = sdhci_am654_restore(host); >> + if (ret) >> + return ret; >> + >> + ret = sdhci_runtime_resume_host(host, 0); >> + if (ret) >> + return ret; >> + >> + ret = cqhci_resume(host->mmc); >> + if (ret) >> + return ret; >> + >> + return 0; >> +} >> +#endif >> + >> +static const struct dev_pm_ops sdhci_am654_dev_pm_ops = { >> + SET_RUNTIME_PM_OPS(sdhci_am654_runtime_suspend, >> + sdhci_am654_runtime_resume, NULL) >> + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, >> + pm_runtime_force_resume) >> +}; >> + >> static struct platform_driver sdhci_am654_driver = { >> .driver = { >> .name = "sdhci-am654", >> .probe_type = PROBE_PREFER_ASYNCHRONOUS, >> + .pm = &sdhci_am654_dev_pm_ops, >> .of_match_table = sdhci_am654_of_match, >> }, >> .probe = sdhci_am654_probe, >> -- >> 2.40.0 >> -- Regards Vignesh
