* Felipe Balbi <balbi@xxxxxx> [151023 09:48]: > > Hi, > > Tony Lindgren <tony@xxxxxxxxxxx> writes: > > From: Tony Lindgren <tony@xxxxxxxxxxx> > > Date: Fri, 23 Oct 2015 09:03:22 -0700 > > Subject: [PATCH] usb: musb: omap2430: Fix regression caused by driver core > > change > > > > Commit ddef08dd00f5 ("Driver core: wakeup the parent device before trying > > probe") started automatically ensuring the parent device is enabled when > > the child gets probed. > > > > This however caused a regression for MUSB omap2430 interface as the > > runtime PM for the parent device needs the child initialized to access > > the MUSB hardware registers. > > > > Let's delay the enabling of PM runtime for the parent until the child > > has been properly initialized as suggested in an earlier patch by > > Grygorii Strashko <grygorii.strashko@xxxxxx>. > > > > In addition to delaying pm_runtime_enable, we now also need to make sure > > the parent is enabled during omap2430_musb_init. We also want to propagate > > an error from omap2430_runtime_resume if struct musb is not initialized. > > > > Note that we use pm_runtime_put_noidle here for both the child and parent > > to prevent an extra runtime_suspend/resume cycle. > > > > Let's also add some comments to avoid confusion between the > > two different devices. > > > > Fixes: ddef08dd00f5 ("Driver core: wakeup the parent device before > > trying probe") > > Suggested-by: Grygorii Strashko <grygorii.strashko@xxxxxx> > > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > > I'm fine with this patch to fix this v4.3 regression. Greg, do you want > a pull request or can you take this in as a patch ? In any case: > > Acked-by: Felipe Balbi <balbi@xxxxxx> OK no response for a few days, so I'll pick this up into omap-for-v4.3/fixes as I have another fix there too. Regards, Tony > > --- a/drivers/usb/musb/omap2430.c > > +++ b/drivers/usb/musb/omap2430.c > > @@ -391,9 +391,20 @@ static int omap2430_musb_init(struct musb *musb) > > } > > musb->isr = omap2430_musb_interrupt; > > > > + /* > > + * Enable runtime PM for musb parent (this driver). We can't > > + * do it earlier as struct musb is not yet allocated and we > > + * need to touch the musb registers for runtime PM. > > + */ > > + pm_runtime_enable(glue->dev); > > + status = pm_runtime_get_sync(glue->dev); > > + if (status < 0) > > + goto err1; > > + > > status = pm_runtime_get_sync(dev); > > if (status < 0) { > > dev_err(dev, "pm_runtime_get_sync FAILED %d\n", status); > > + pm_runtime_put_sync(glue->dev); > > goto err1; > > } > > > > @@ -426,6 +437,7 @@ static int omap2430_musb_init(struct musb *musb) > > phy_power_on(musb->phy); > > > > pm_runtime_put_noidle(musb->controller); > > + pm_runtime_put_noidle(glue->dev); > > return 0; > > > > err1: > > @@ -626,7 +638,11 @@ static int omap2430_probe(struct platform_device *pdev) > > goto err2; > > } > > > > - pm_runtime_enable(&pdev->dev); > > + /* > > + * Note that we cannot enable PM runtime yet for this > > + * driver as we need struct musb initialized first. > > + * See omap2430_musb_init above. > > + */ > > > > ret = platform_device_add(musb); > > if (ret) { > > @@ -675,11 +691,12 @@ static int omap2430_runtime_resume(struct device *dev) > > struct omap2430_glue *glue = dev_get_drvdata(dev); > > struct musb *musb = glue_to_musb(glue); > > > > - if (musb) { > > - omap2430_low_level_init(musb); > > - musb_writel(musb->mregs, OTG_INTERFSEL, > > - musb->context.otg_interfsel); > > - } > > + if (!musb) > > + return -EPROBE_DEFER; > > + > > + omap2430_low_level_init(musb); > > + musb_writel(musb->mregs, OTG_INTERFSEL, > > + musb->context.otg_interfsel); > > > > return 0; > > } > > -- > balbi -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html