From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754556AbdGJTr1 (ORCPT ); Mon, 10 Jul 2017 15:47:27 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:53827 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754152AbdGJTr0 (ORCPT ); Mon, 10 Jul 2017 15:47:26 -0400 From: Laurent Pinchart To: Jim Lin Cc: mchehab@kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH 1/1 V2] media: usb: uvc: Fix incorrect timeout for Get Request Date: Mon, 10 Jul 2017 22:47:28 +0300 Message-ID: <3026364.oSOK2ZPSm0@avalon> User-Agent: KMail/4.14.10 (Linux/4.9.34-gentoo; KDE/4.14.32; x86_64; ; ) In-Reply-To: <1499669029-3412-1-git-send-email-jilin@nvidia.com> References: <1499669029-3412-1-git-send-email-jilin@nvidia.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jim, Thank you for the patch. On Monday 10 Jul 2017 14:43:49 Jim Lin wrote: > Section 9.2.6.4 of USB 2.0/3.x specification describes that > "device must be able to return the first data packet to host within > 500 ms of receipt of the request. For subsequent data packet, if any, > the device must be able to return them within 500 ms". > > This is to fix incorrect timeout and change it from 300 ms to 500 ms > to meet the timing specified by specification for Get Request. > > Signed-off-by: Jim Lin The patch looks good to me, so Reviewed-by: Laurent Pinchart but I'm curious, have you noticed issues with some devices in practice ? > --- > V2: Change patch description > > drivers/media/usb/uvc/uvcvideo.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/usb/uvc/uvcvideo.h > b/drivers/media/usb/uvc/uvcvideo.h index 15e415e..296b69b 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -166,7 +166,7 @@ > /* Maximum status buffer size in bytes of interrupt URB. */ > #define UVC_MAX_STATUS_SIZE 16 > > -#define UVC_CTRL_CONTROL_TIMEOUT 300 > +#define UVC_CTRL_CONTROL_TIMEOUT 500 > #define UVC_CTRL_STREAMING_TIMEOUT 5000 > > /* Maximum allowed number of control mappings per device */ -- Regards, Laurent Pinchart