Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751655AbbFYQV4 (ORCPT ); Thu, 25 Jun 2015 12:21:56 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:48373 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750968AbbFYQVt (ORCPT ); Thu, 25 Jun 2015 12:21:49 -0400 X-Sasl-enc: FRdYxjw9SYPskHeoQhPfOtrIrCkThVrtzGVjEhD/3lyW 1435249306 Date: Thu, 25 Jun 2015 13:21:43 -0300 From: Henrique de Moraes Holschuh To: Jeff Chua Cc: Linux Kernel , Christoph Hellwig , Greg Kroah-Hartman Subject: Re: Stop SSD from waiting for "Spinning up disk..." Message-ID: <20150625162143.GA27230@khazad-dum.debian.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-GPG-Fingerprint1: 4096R/39CB4807 C467 A717 507B BAFE D3C1 6092 0BD9 E811 39CB 4807 X-GPG-Fingerprint2: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 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 Content-Length: 1229 Lines: 28 On Mon, 22 Jun 2015, Jeff Chua wrote: > There's no need to wait for disk spin-up for USB SSD devices. This patch No, you have to, instead, wait for SSD firmware startup. And looking at the contents of sd_spinup_disk(), I don't think it is safe to just skip it, either. It would be be better to call it sd_start_device()... sd_spinup_disk() should be really fast on anything that properly implements TEST_UNIT_READY and returns "ok, I am ready" when it doesn't need further waits or START_STOP, etc... Anyway, if you get to see the "Spinning up disk..." printk, your unit did not report it was ready, and sd_spinup_disk tried to issue a START_STOP command to signal it to get ready for real work. There's at least one msleep(1000) in the START_STOP path, though. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- 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/