From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:59761 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751209AbbIIIaQ (ORCPT ); Wed, 9 Sep 2015 04:30:16 -0400 Subject: Re: [PATCH v1] media: uvcvideo: handle urb completion in a work queue To: Alan Stern References: Cc: Mian Yousaf Kaukab , laurent.pinchart@ideasonboard.com, linux-media@vger.kernel.org, mchehab@osg.samsung.com, linux-usb@vger.kernel.org From: Hans de Goede Message-ID: <55EFEE14.5050100@redhat.com> Date: Wed, 9 Sep 2015 10:30:12 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi, On 08-09-15 16:36, Alan Stern wrote: > On Tue, 8 Sep 2015, Hans de Goede wrote: > >> Hi, >> >> On 09/07/2015 06:23 PM, Mian Yousaf Kaukab wrote: >>> urb completion callback is executed in host controllers interrupt >>> context. To keep preempt disable time short, add urbs to a list on >>> completion and schedule work to process the list. >>> >>> Moreover, save timestamp and sof number in the urb completion callback >>> to avoid any delays. >> >> Erm, I thought that we had already moved to using threaded interrupt >> handling for the urb completion a while (1-2 years ?) back. Is this then >> still needed ? > > We moved to handling URB completions in a tasklet, not a threaded > handler. Right. > (Similar idea, though.) And the change was made in only one > or two HCDs, not in all of them. Ah, I was under the impression this was a core change, not a per hcd change. Regards, Hans