Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753391AbbBQVS2 (ORCPT ); Tue, 17 Feb 2015 16:18:28 -0500 Received: from mail-lb0-f173.google.com ([209.85.217.173]:40179 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752880AbbBQVSY (ORCPT ); Tue, 17 Feb 2015 16:18:24 -0500 From: Ruslan Bilovol To: balbi@ti.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, k.opasiak@samsung.com, stern@rowland.harvard.edu, peter.chen@freescale.com, gregkh@linuxfoundation.org, andrzej.p@samsung.com Subject: [PATCHv3 5/5] usb: gadget: udc-core: independent registration of gadgets and gadget drivers Date: Tue, 17 Feb 2015 23:17:57 +0200 Message-Id: <1424207877-30915-6-git-send-email-ruslan.bilovol@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1424207877-30915-1-git-send-email-ruslan.bilovol@gmail.com> References: <1424207877-30915-1-git-send-email-ruslan.bilovol@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5028 Lines: 162 Change behavior during registration of gadgets and gadget drivers in udc-core. Instead of previous approach when for successful probe of usb gadget driver at least one usb gadget should be already registered use another one where gadget drivers and gadgets can be registered in udc-core independently. Independent registration of gadgets and gadget drivers is useful for built-in into kernel gadget and gadget driver case - because it's possible that gadget is really probed only on late_init stage (due to deferred probe) whereas gadget driver's probe is silently failed on module_init stage due to no any UDC added. Also it is useful for modules case - now there is no difference what module to insert first: gadget module or gadget driver one. Signed-off-by: Ruslan Bilovol --- drivers/usb/gadget/udc/udc-core.c | 51 ++++++++++++++++++++++++++++++--------- include/linux/usb/gadget.h | 2 ++ 2 files changed, 42 insertions(+), 11 deletions(-) diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c index a960f3f..9e82497 100644 --- a/drivers/usb/gadget/udc/udc-core.c +++ b/drivers/usb/gadget/udc/udc-core.c @@ -48,8 +48,11 @@ struct usb_udc { static struct class *udc_class; static LIST_HEAD(udc_list); +static LIST_HEAD(gadget_driver_pending_list); static DEFINE_MUTEX(udc_lock); +static int udc_bind_to_driver(struct usb_udc *udc, + struct usb_gadget_driver *driver); /* ------------------------------------------------------------------------- */ #ifdef CONFIG_HAS_DMA @@ -243,6 +246,7 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)) { struct usb_udc *udc; + struct usb_gadget_driver *pgadget; int ret = -ENOMEM; udc = kzalloc(sizeof(*udc), GFP_KERNEL); @@ -288,6 +292,18 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED); + /* pick up one of pending gadget drivers */ + list_for_each_entry(pgadget, &gadget_driver_pending_list, pending) { + if (!pgadget->udc_name || strcmp(pgadget->udc_name, + dev_name(&udc->dev)) == 0) { + ret = udc_bind_to_driver(udc, pgadget); + if (ret) + goto err4; + list_del(&pgadget->pending); + break; + } + } + mutex_unlock(&udc_lock); return 0; @@ -364,10 +380,11 @@ found: dev_vdbg(gadget->dev.parent, "unregistering gadget\n"); list_del(&udc->list); - mutex_unlock(&udc_lock); - - if (udc->driver) + if (udc->driver) { + list_add(&udc->driver->pending, &gadget_driver_pending_list); usb_gadget_remove_driver(udc); + } + mutex_unlock(&udc_lock); kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); flush_work(&gadget->work); @@ -426,24 +443,26 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver) if (!ret) break; } - if (ret) - ret = -ENODEV; - else if (udc->driver) - ret = -EBUSY; - else + if (!ret && udc->driver) { + mutex_unlock(&udc_lock); + return -EBUSY; + } else if (!ret) { goto found; + } } else { list_for_each_entry(udc, &udc_list, list) { /* For now we take the first one */ if (!udc->driver) goto found; } - ret = -ENODEV; } - pr_debug("couldn't find an available UDC\n"); + list_add_tail(&driver->pending, &gadget_driver_pending_list); + pr_info("udc-core: couldn't find an available UDC " + "- added [%s] to list of pending drivers\n", + driver->function); mutex_unlock(&udc_lock); - return ret; + return 0; found: ret = udc_bind_to_driver(udc, driver); mutex_unlock(&udc_lock); @@ -469,6 +488,16 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver) break; } + if (ret) { + struct usb_gadget_driver *tmp; + + list_for_each_entry(tmp, &gadget_driver_pending_list, pending) + if (tmp == driver) { + list_del(&driver->pending); + ret = 0; + break; + } + } mutex_unlock(&udc_lock); return ret; } diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index 6070e8d..3878425 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -823,6 +823,7 @@ static inline int usb_gadget_disconnect(struct usb_gadget *gadget) * @driver: Driver model state for this driver. * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL, * this driver will be bound to any available UDC. + * @pending: UDC core private data used for deferred probe of this driver. * * Devices are disabled till a gadget driver successfully bind()s, which * means the driver will handle setup() requests needed to enumerate (and @@ -885,6 +886,7 @@ struct usb_gadget_driver { struct device_driver driver; char *udc_name; + struct list_head pending; }; -- 1.9.1 -- 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/