Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756181AbbDGPwn (ORCPT ); Tue, 7 Apr 2015 11:52:43 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:33963 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755504AbbDGPwk (ORCPT ); Tue, 7 Apr 2015 11:52:40 -0400 Date: Tue, 7 Apr 2015 11:52:39 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Ramneek Mehresh cc: linux-kernel@vger.kernel.org, , , Subject: Re: [PATCH 2/9][v2]usb:fsl:otg: Add support to add/remove usb host driver In-Reply-To: <1428407919-24655-2-git-send-email-ramneek.mehresh@freescale.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3155 Lines: 95 On Tue, 7 Apr 2015, Ramneek Mehresh wrote: > Add workqueue to add/remove host driver (outside interrupt context) > upon each id change This patch needs to be fixed. See below. > Signed-off-by: Ramneek Mehresh > --- > drivers/usb/host/ehci-fsl.c | 107 ++++++++++++++++++++++++++++++++++++-------- > drivers/usb/host/ehci.h | 1 - > 2 files changed, 88 insertions(+), 20 deletions(-) > > diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c > index ab4eee3..9c91fbe 100644 > --- a/drivers/usb/host/ehci-fsl.c > +++ b/drivers/usb/host/ehci-fsl.c > @@ -33,6 +33,58 @@ > > #include "ehci-fsl.h" > > +struct ehci_fsl { > + struct ehci_hcd ehci; > + > +#ifdef CONFIG_PM > + /* Saved USB PHY settings, need to restore after deep sleep. */ > + u32 usb_ctrl; > +#if defined(CONFIG_FSL_USB2_OTG) || defined(CONFIG_FSL_USB2_OTG_MODULE) > + struct work_struct change_hcd_work; > +#endif > +#endif > + > + /* store current hcd state for otg; > + * have_hcd is true when host drv al already part of otg framework, > + * otherwise false; > + * hcd_add is true when otg framework wants to add host > + * drv as part of otg;flase when it wants to remove it > + */ > + unsigned have_hcd:1; > + unsigned hcd_add:1; > +}; This is the wrong way to connect platform-private data with the ehci_hcd structure. The right way is to use an ehci_driver_overrides structure, like in ehci-omap.c and quite a few other EHCI platform drivers. > +#if defined(CONFIG_FSL_USB2_OTG) || defined(CONFIG_FSL_USB2_OTG_MODULE) > +static struct ehci_fsl *hcd_to_ehci_fsl(struct usb_hcd *hcd) > +{ > + struct ehci_hcd *ehci = hcd_to_ehci(hcd); > + > + return container_of(ehci, struct ehci_fsl, ehci); > +} This is bound to fail no matter what, because the ehci_hcd structure is already embedded in the usb_hcd structure. It can't be embedded in an ehci_fsl structure too. (Of course, this won't matter when you switch to the approved way of connecting private data.) > +static void do_change_hcd(struct work_struct *work) > +{ > + struct ehci_fsl *ehci_fsl = container_of(work, struct ehci_fsl, > + change_hcd_work); > + struct ehci_hcd *ehci = &ehci_fsl->ehci; > + struct usb_hcd *hcd = ehci_to_hcd(ehci); > + > + void __iomem *non_ehci = hcd->regs; > + int retval; > + > + if (ehci_fsl->hcd_add && !ehci_fsl->have_hcd) { > + writel(USBMODE_CM_HOST, non_ehci + FSL_SOC_USB_USBMODE); > + /* host, gadget and otg share same int line */ > + retval = usb_add_hcd(hcd, hcd->irq, IRQF_SHARED); > + if (retval == 0) > + ehci_fsl->have_hcd = 1; > + } else if (!ehci_fsl->hcd_add && ehci_fsl->have_hcd) { > + usb_remove_hcd(hcd); > + ehci_fsl->have_hcd = 0; > + } > +} Does this really work right? What about things like device_wakeup_enable()? Don't you need to disable the controller when leaving host mode and enable it when entering host mode? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/