Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752244AbcLFKB7 (ORCPT ); Tue, 6 Dec 2016 05:01:59 -0500 Received: from web01.01d.eu ([5.200.27.195]:50954 "EHLO web01.01d.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752057AbcLFKB4 (ORCPT ); Tue, 6 Dec 2016 05:01:56 -0500 Subject: Re: [PATCH v2] Staging: dgnc: dgnc_*.c: Use usleep_range over udelay to improve coalescing processor wakeups To: Greg KH References: <20161206085958.5286-1-shiva@exdev.nl> <20161206091222.GA12130@kroah.com> Cc: lidza.louina@gmail.com, markh@compro.net, driverdev-devel@linuxdriverproject.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org From: Shiva Kerdel Message-ID: <269ff7f4-c8f2-347e-835a-a5509bbb739a@exdev.nl> Date: Tue, 6 Dec 2016 11:01:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161206091222.GA12130@kroah.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Id: shiva@exdev.nl Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 644 Lines: 16 > On Tue, Dec 06, 2016 at 09:59:58AM +0100, Shiva Kerdel wrote: >> In most cases, usleep_range is better than udelay, as the precise wakeup >> from udelay is unnecessary. > But, udelay does something different than usleep, are you sure you > should be giving up the cpu at this point in time? > > Are you sure you are even in a function that is allowed to sleep? I > don't think that is the case for all of these at all, sorry, unless you > have the hardware to test this change, I can't take it. > > greg k-h I wasn't aware of this, thank you for pointing out. Since I don't have this hardware, I'm unable to test the changes. Shiva Kerdel