From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [tegrarcm PATCH v1 4/4] Increate USB timeout value Date: Mon, 7 Mar 2016 12:39:55 -0700 Message-ID: <56DDD90B.1040802@wwwdotorg.org> References: <1457135087-967-1-git-send-email-jimmzhang@nvidia.com> <1457135087-967-5-git-send-email-jimmzhang@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1457135087-967-5-git-send-email-jimmzhang-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jimmy Zhang Cc: amartin-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, alban.bedel-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 03/04/2016 04:44 PM, Jimmy Zhang wrote: > It has been observed that some times USB time out could occure when a long (3ft) > usb cable is connected to recovery mode usb port This explanation makes no sense. 3ft is practically the shortest USB cable anyone would use. Equally, assuming a compliant correctly functioning cable, cable length doesn't affect the time it takes to execute transactions. Is the issue more that if a low quality cable is used, then there are lots of transfer errors, and the time taken for retries is large? If so, there's not much guarantee that a larger timeout would help in general, since there's no guarantee of any upper bound on the time it takes for a packet not to get corrupted in this case. Still, I suppose it's fine to increase the timeout to account for when it accidentally works. In summary: a commit description that more accurately represents the problem being solved is required.