From mboxrd@z Thu Jan 1 00:00:00 1970 From: grygorii.strashko@ti.com (Grygorii Strashko) Date: Fri, 23 Oct 2015 15:50:21 +0300 Subject: MUSB peripheral DMA regression caused by driver core runtime PM change In-Reply-To: <20151022230133.GV3078@atomide.com> References: <20151021234134.GQ3078@atomide.com> <20151022180216.GT3078@atomide.com> <20151022230133.GV3078@atomide.com> Message-ID: <562A2D0D.3060104@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/23/2015 02:01 AM, Tony Lindgren wrote: > * Tony Lindgren [151022 11:03]: >> * Tony Lindgren [151021 16:44]: >>> Hi all, >>> >>> I noticed a regresssino in v4.3-rc series to day with MUSB gadgets >>> and DMA. Doing a git bisect between v4.2..v4.3-rc1 on it pointed to: >>> >>> ddef08dd00f5 ("Driver core: wakeup the parent device before trying probe") >>> >>> With the commit above reverted things work fine with DMA and USB gadgets. >>> >>> This is on omap3 with CONFIG_USB_INVENTRA_DMA selected. Selecting >>> CONFIG_MUSB_PIO_ONLY still works even without reverting ddef08dd00f5. >>> >>> Anybody got ideas what might be wrong? Some wrong runtime PM usage >>> under drivers/usb/musb? >> >> Here's some more debug info on where things are different initializing >> the USB gadgets. I added some printks and diffed the dmesg output. The >> added calls from commit ddef08dd00f5 start with dd: > > Well turns out the problem actually happens earlier. We end up calling > omap2430_runtime_resume with NULL struct musb while EPROBE_DEFER > probing. > > No ideas yet how it should be fixed though. > I'm not sure, but below diff might help diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c index 70f2b8a..aba8ca7 100644 --- a/drivers/usb/musb/omap2430.c +++ b/drivers/usb/musb/omap2430.c @@ -391,6 +391,8 @@ static int omap2430_musb_init(struct musb *musb) } musb->isr = omap2430_musb_interrupt; + pm_runtime_enable(glue->dev); + status = pm_runtime_get_sync(dev); if (status < 0) { dev_err(dev, "pm_runtime_get_sync FAILED %d\n", status); @@ -626,8 +628,6 @@ static int omap2430_probe(struct platform_device *pdev) goto err2; } - pm_runtime_enable(&pdev->dev); - ret = platform_device_add(musb); if (ret) { dev_err(&pdev->dev, "failed to register musb device\n"); -- regards, -grygorii