Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751748AbaLWSbr (ORCPT ); Tue, 23 Dec 2014 13:31:47 -0500 Received: from devils.ext.ti.com ([198.47.26.153]:47138 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbaLWSbp (ORCPT ); Tue, 23 Dec 2014 13:31:45 -0500 Date: Tue, 23 Dec 2014 12:31:20 -0600 From: Felipe Balbi To: Robert Baldyga CC: , Peter Chen , , , , , Subject: Re: [PATCH] usb: gadget: udc-core: call udc_stop() before gadget unbind Message-ID: <20141223183120.GG9147@saruman> Reply-To: References: <1418390248-6254-1-git-send-email-r.baldyga@samsung.com> <20141215051317.GC25410@shlinux2> <548EB262.6040208@samsung.com> <20141222163430.GH12815@saruman> <54990CE7.1030008@samsung.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="E69HUUNAyIJqGpVn" Content-Disposition: inline In-Reply-To: <54990CE7.1030008@samsung.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --E69HUUNAyIJqGpVn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Dec 23, 2014 at 07:34:15AM +0100, Robert Baldyga wrote: > Hi Felipe, >=20 > On 12/22/2014 05:34 PM, Felipe Balbi wrote: > > On Mon, Dec 15, 2014 at 11:05:22AM +0100, Robert Baldyga wrote: > >> On 12/15/2014 06:13 AM, Peter Chen wrote: > >>> On Fri, Dec 12, 2014 at 02:17:28PM +0100, Robert Baldyga wrote: > >>>> As usb function drivers assumes that all usb request will be complet= ed > >>>> before function unbind call, we should supply such behavior. In some > >>>> cases ep_disable() won't kill all request effectively, because some > >>>> IN requests can be in running state. In such situation it's possible > >>>> to have unbind function called before last request completion, which > >>>> can cause problems. > >>> > >>> Doesn't the function's disable/unbind should call usb_ep_dequeue to m= ake > >>> sure the transfer has ended? > >> > >> USB function drivers like ECM or HID surely doesn't. It looks like > >> there's assumption that all requests will be completed by UDC driver. > >=20 > > that's a bug on those drivers :-) >=20 > So we can't make assumptions that requests will be completed in > ep_disable()? oh, no you can. I misread it. > >> Function ep_disable() should complete requests in hardware driver, but > >> at least in DWC2 driver not all requests are completed at this stage > >=20 > > and that's a bug on dwc2 :-) >=20 > I have already found that out. Another UDC drivers simply kill all > request without waiting for currently running, so I did the same in > DWC2. Here is my patch: > http://www.spinics.net/lists/linux-usb/msg118698.html should be in my pull request already. > >> (request which are in hardware FIFO are omitted to give them chance to > >> be transferred). Those requests are forced to complete in udc_stop() > >=20 > > that's wrong, we're disabling the endpoint anyway. Either dwc2 needs to > > wait_for_completion() or forcibly cancel the request. The bottom line is > > that control should not exit ep_disable() until all requests have been > > quiesced. >=20 > So that's not bug in function drivers. They make correct assumption, > because they expect that requests will be completed in ep_disable(). right :-) --=20 balbi --E69HUUNAyIJqGpVn Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUmbT4AAoJEIaOsuA1yqRElzgP/2ldPEi92cbdOZO82r6j0/Fa suDaHNZzYe3sOI7Ew7taPrj1XXN4O79/7DOjUBXjMv0fc2sn6Mc7+HDa0IzlK2RQ pK+6P+/VqaigE46FSOMkAHv+qlKMuGak2V2vtqcWvYtfJBoTZBmhs47Xc494RMPa tT0QaFAtfzNBcoG0A3VDWYaIoRirkCw/G0uKUOuX2VwzbVHOe2JFgHeazm4omugX GFJ0mXgzVKksNB+imotbxv+6Wje9Oxh8tCm1sjirXavc2e0MTH9BSkgW7ZRQuCw3 nBZl99J+Y/d6MiwmCIQFw9fM4VNvxtqW/HOoqhywwBMfpbLnRfqTlrnT1uVxVbgX fEQPD3R1jGfgedv2X6xVwGBoC/UJuqv36bPcYgqaLmA9cjEMcvlAp4AAmqtR0Caw 5FviU2zbkl0TKGkmC6hIicFZ48q7Oes4yCsFu/LZgzu9mmmXa9vRZQ2Z6PeG1U33 r35TQ1dEK0TsJr3aBXJNz6MuBhmocONnuJYKdLTSY5vxJhYCu774QLljCpfKRtTD zma1wvXaF+PQPuXXs+KGeB/M2cA0MAJkE9r1pPpcUV5jKeqHLdt9MqnPmDkt5fzB qLOzu+MFUv/QHFbfDrdVD5ZdfS0Xhj7auh74R6HJkkcwHqXL8FbKo6uyELKmTMhc J+Z0gz01MHz7rVqZzpO2 =8VoC -----END PGP SIGNATURE----- --E69HUUNAyIJqGpVn-- -- 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/