Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757136Ab3GRIkz (ORCPT ); Thu, 18 Jul 2013 04:40:55 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:38734 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756376Ab3GRIkw (ORCPT ); Thu, 18 Jul 2013 04:40:52 -0400 Date: Thu, 18 Jul 2013 11:40:41 +0300 From: Felipe Balbi To: Rong Wang CC: , Greg KH , Arnd Bergmann , , , Subject: Re: [PATCH] usb: udc: add gadget state kobject uevent Message-ID: <20130718084041.GE11251@arwen.pp.htv.fi> Reply-To: References: <20130715165209.GA6000@kroah.com> <20130716063117.GA30320@kroah.com> <20130717075706.GC5291@arwen.pp.htv.fi> <20130717132736.GA7614@arwen.pp.htv.fi> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="5Mfx4RzfBqgnTE/w" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6459 Lines: 187 --5Mfx4RzfBqgnTE/w Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Thu, Jul 18, 2013 at 04:33:43PM +0800, Rong Wang wrote: > On Wed, Jul 17, 2013 at 9:27 PM, Felipe Balbi wrote: > > On Wed, Jul 17, 2013 at 09:04:54PM +0800, Rong Wang wrote: > >> Hi Felipe, > >> > >> On Wed, Jul 17, 2013 at 3:57 PM, Felipe Balbi wrote: > >> > Hi, > >> > > >> > On Mon, Jul 15, 2013 at 11:31:17PM -0700, Greg KH wrote: > >> >> > The question is since we default GADGET, so the g_mass_storage.ko= is > >> >> > installed early but connecting to a host PC > >> >> > is randomly, But the udev has no idea when a host PC connects our= device. > >> >> > > >> >> > So we consider it's reasonable to let the udev know the GADGET de= vice state. > >> >> > Is there any alternative to our question? > >> >> > >> >> I thought we already export events for gadget device states, have y= ou > >> >> looked for them? I can't dig through the code at the moment, but t= his > >> >> seems like a pretty common issue... > >> >> > >> >> Felipe, any ideas? > >> > > >> > we already expose that in sysfs. IIRC udev can act on sysfs changes, > >> > no ? > >> > >> I do not know if udev can polling sysfs file content change. I'll stud= y this. > >> > >> But the change is triggered by calling usb_gadget_set_state, and I find > >> composite framework do not call this. Then we should do this common wo= rk > >> in every udc driver? > > > > yes. Only the UDC driver knows when the controller is moving among those > > states. >=20 > OK. I got that. >=20 > But I think it may be more reasonable for the udc driver to maintain a > work queue > to handle the state change since this operation mostly happen in ISR ? And that's the patch I want to test. Adding a workqueue to every single UDC will be too much, so I tried to hide it in udc-core.c. I agree with you we need to pass the sysfs_notification to a separate workqueue though. If you can test the patch below, that would be great. commit d32521bd775d48b600e67f23d363d70f71597ffd Author: Felipe Balbi Date: Wed Jul 17 11:09:49 2013 +0300 usb: gadget: udc-core: move sysfs_notify() to a workqueue =20 usb_gadget_set_state() will call sysfs_notify() which might sleep. Some users might want to call usb_gadget_set_state() from the very IRQ handler which actually changes the gadget state. =20 Instead of having every UDC driver add their own workqueue for such a simple notification, we're adding it generically to our struct usb_gadget, so the details are hidden from all UDC drivers. =20 Signed-off-by: Felipe Balbi diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c index ffd8fa5..b0d91b1 100644 --- a/drivers/usb/gadget/udc-core.c +++ b/drivers/usb/gadget/udc-core.c @@ -23,6 +23,7 @@ #include #include #include +#include =20 #include #include @@ -101,11 +102,18 @@ EXPORT_SYMBOL_GPL(usb_gadget_unmap_request); =20 /* -----------------------------------------------------------------------= -- */ =20 +static void usb_gadget_state_work(struct work_struct *work) +{ + struct usb_gadget *gadget =3D work_to_gadget(work); + + sysfs_notify(&gadget->dev.kobj, NULL, "status"); +} + void usb_gadget_set_state(struct usb_gadget *gadget, enum usb_device_state state) { gadget->state =3D state; - sysfs_notify(&gadget->dev.kobj, NULL, "status"); + schedule_work(&gadget->work); } EXPORT_SYMBOL_GPL(usb_gadget_set_state); =20 @@ -192,6 +200,7 @@ int usb_add_gadget_udc_release(struct device *parent, s= truct usb_gadget *gadget, goto err1; =20 dev_set_name(&gadget->dev, "gadget"); + INIT_WORK(&gadget->work, usb_gadget_state_work); gadget->dev.parent =3D parent; =20 dma_set_coherent_mask(&gadget->dev, parent->coherent_dma_mask); diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index f1b0dca..942ef5e 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -22,6 +22,7 @@ #include #include #include +#include #include =20 struct usb_ep; @@ -475,6 +476,7 @@ struct usb_gadget_ops { =20 /** * struct usb_gadget - represents a usb slave device + * @work: (internal use) Workqueue to be used for sysfs_notify() * @ops: Function pointers used to access hardware-specific operations. * @ep0: Endpoint zero, used when reading or writing responses to * driver setup() requests @@ -520,6 +522,7 @@ struct usb_gadget_ops { * device is acting as a B-Peripheral (so is_a_peripheral is false). */ struct usb_gadget { + struct work_struct work; /* readonly to gadget driver */ const struct usb_gadget_ops *ops; struct usb_ep *ep0; @@ -538,6 +541,7 @@ struct usb_gadget { unsigned out_epnum; unsigned in_epnum; }; +#define work_to_gadget(w) (container_of((w), struct usb_gadget, work)) =20 static inline void set_gadget_data(struct usb_gadget *gadget, void *data) { dev_set_drvdata(&gadget->dev, data); } --=20 balbi --5Mfx4RzfBqgnTE/w Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJR56oIAAoJEIaOsuA1yqRE9sQP/RLPI2MSJZ29QsxI7lBoSEHS p808Xhf5JINmVRwv+Q9i5+bFBWQUNZ16t+63JE4b6Ym8uDht0ldNU12jaFBm3M9/ BKZ+w8TnSuxVE0tGvlOigGEG6m3QxwTmYQAWmu0bb6FwA6yrcnPLXdczPCkOdy/E ePynFTyDDxqmEnCBeCWnOzwS/efqmQVNpVIsorsDSriMV6Cj06kgCo43ZrtitWfA pHIm47bE4IZrI/xxxp573EqttSQPqJ5iAFai8BWDrry7OKrFBqohBk9HdeJuPZ1Q lRJVkT8yykGebDkxCmJRL3hqztveJVkPaHWj6yMHRwEib/pwZTkeXynfCoxk2G6e R1Nex6Losk+zkszQK3RAKTQ2bWRpyiXtMO9SbOjQYyccgJeEQS+WFXlZsXhyTkx0 Gvwqe4F/JoKy0h7ATK3gmQ6M6xCPRgg39fclFHD2909syc6Lc2R/C7g9vaeCuzWB 0p7uPUJZlUhcuD4tgjmcZE09VE3BdLxC3PPM5k270sCGzl3AbdDoERzDjQ+sLriQ H2eu4oX5KpRvMEX4wPpt/lPSZk+bcU8CyPkKEu765Nu/w+BsgVokYUOfYV2CChha YR7t2ZIFPqFyi7rwYxavbe/qEMXmAnvFlnclxhsJ11oBIX8Xhc2Q4Y4dg1pCpa69 CsLwFKJDoNOofNV6oRyb =+5wB -----END PGP SIGNATURE----- --5Mfx4RzfBqgnTE/w-- -- 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/