On Mon, 3 Apr 2023 at 19:42, Vignesh Raghavendra <vigneshr@xxxxxx> wrote: > > 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. Ohh, that kind of sucks. There is no way to workaround that I guess? > > > [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) Alright, makes sense! > > One solution is to use -1 on platforms where latency is significant > based on compatible / SoC detection? That's a good idea! It seems a pity to make all SoCs suffer, if there is only a subset that has this problem. Although, let's consider that as an improvement that can be done on top of $subject patch. So, applied for next, thanks! 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
