Hi Maxime, On 16/04/18 15:23, Maxime Ripard wrote: > So far, even if our card was not in use, we didn't shut down our MMC > controller, which meant that it was still active and clocking the bus. > > While this obviously means that we could save some power there, it also > creates issues when it comes to EMC control since we'll have a perfect peak > at the card clock rate. > > Let's implement runtime_pm with autosuspend so that we will shut down the > controller when it's not been in use for quite some time. > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx> > --- > drivers/mmc/host/sunxi-mmc.c | 48 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 48 insertions(+) > > diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c > index 0165da0d022a..0253deb153a4 100644 > --- a/drivers/mmc/host/sunxi-mmc.c > +++ b/drivers/mmc/host/sunxi-mmc.c > @@ -35,6 +35,7 @@ > #include <linux/of_gpio.h> > #include <linux/of_platform.h> > #include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > #include <linux/regulator/consumer.h> > #include <linux/reset.h> > #include <linux/scatterlist.h> > @@ -969,6 +970,9 @@ static void sunxi_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable) > unsigned long flags; > u32 imask; > > + if (enable) > + pm_runtime_get_noresume(host->dev); > + > spin_lock_irqsave(&host->lock, flags); > > imask = mmc_readl(host, REG_IMASK); > @@ -981,6 +985,9 @@ static void sunxi_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable) > } > mmc_writel(host, REG_IMASK, imask); > spin_unlock_irqrestore(&host->lock, flags); > + > + if (!enable) > + pm_runtime_put_noidle(host->mmc->parent); > } > > static void sunxi_mmc_hw_reset(struct mmc_host *mmc) > @@ -1394,6 +1401,11 @@ static int sunxi_mmc_probe(struct platform_device *pdev) > if (ret) > goto error_free_dma; > > + pm_runtime_set_active(&pdev->dev); > + pm_runtime_set_autosuspend_delay(&pdev->dev, 50); > + pm_runtime_use_autosuspend(&pdev->dev); > + pm_runtime_enable(&pdev->dev); > + > ret = mmc_add_host(mmc); > if (ret) > goto error_free_dma; > @@ -1414,6 +1426,7 @@ static int sunxi_mmc_remove(struct platform_device *pdev) > struct sunxi_mmc_host *host = mmc_priv(mmc); > > mmc_remove_host(mmc); > + pm_runtime_force_suspend(&pdev->dev); > disable_irq(host->irq); > sunxi_mmc_disable(host); > dma_free_coherent(&pdev->dev, PAGE_SIZE, host->sg_cpu, host->sg_dma); > @@ -1422,10 +1435,45 @@ static int sunxi_mmc_remove(struct platform_device *pdev) > return 0; > } > > +static int sunxi_mmc_runtime_resume(struct device *dev) > +{ > + struct mmc_host *mmc = dev_get_drvdata(dev); > + struct sunxi_mmc_host *host = mmc_priv(mmc); > + int ret; > + > + ret = sunxi_mmc_enable(host); > + if (ret) > + return ret; > + > + sunxi_mmc_init_host(host); > + sunxi_mmc_set_bus_width(host, mmc->ios.bus_width); > + sunxi_mmc_set_clk(host, &mmc->ios); > + > + return 0; > +} > + > +static int sunxi_mmc_runtime_suspend(struct device *dev) > +{ > + struct mmc_host *mmc = dev_get_drvdata(dev); > + struct sunxi_mmc_host *host = mmc_priv(mmc); > + > + sunxi_mmc_reset_host(host); > + sunxi_mmc_disable(host); > + > + return 0; > +} > + > +static const struct dev_pm_ops sunxi_mmc_pm_ops = { > + SET_RUNTIME_PM_OPS(sunxi_mmc_runtime_suspend, > + sunxi_mmc_runtime_resume, > + NULL) > +}; > + > static struct platform_driver sunxi_mmc_driver = { > .driver = { > .name = "sunxi-mmc", > .of_match_table = of_match_ptr(sunxi_mmc_of_match), > + .pm = &sunxi_mmc_pm_ops, > }, > .probe = sunxi_mmc_probe, > .remove = sunxi_mmc_remove, > This patch has the unfortunate impact of killing my A20 system (cubietruck), as of 9a8e1e8cc2c02c57c4e941651a8481a633506c91: [...] [ 3.286649] NET: Registered protocol family 10 [ 3.291898] mmcblk0: p1 [ 3.295297] mmc1: queuing unknown CIS tuple 0x80 (2 bytes) [ 3.302773] mmc1: queuing unknown CIS tuple 0x80 (3 bytes) [ 3.305787] Segment Routing with IPv6 [ 3.312225] mip6: Mobile IPv6 [ 3.316166] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver [ 3.316246] mmc1: queuing unknown CIS tuple 0x80 (3 bytes) [ 3.323721] ip6_gre: GRE over IPv6 tunneling driver [ 3.333954] NET: Registered protocol family 17 [ 3.338837] 9pnet: Installing 9P2000 support [ 3.343379] NET: Registered protocol family 37 [ 3.347885] Key type dns_resolver registered [ 3.352214] mmc1: queuing unknown CIS tuple 0x80 (7 bytes) [ 3.352217] openvswitch: Open vSwitch switching datapath [ 3.352620] mpls_gso: MPLS GSO support [ 3.367001] ThumbEE CPU extension supported. and that's where it stops. No message, just a hard lockup (I suppose that both the CPUs are trying to access some device that is now not clocked). With a working kernel, I see SATA and the wifi SDIO being probed. Happy to help testing stuff if you have any idea. Thanks, M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html