From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Cartwright Subject: Re: [PATCHv4 4/7] hwspinlock/core: add common OF helpers Date: Fri, 14 Mar 2014 10:23:04 -0500 Message-ID: <20140314152304.GS18529@joshc.qualcomm.com> References: <1389658764-39199-1-git-send-email-s-anna@ti.com> <1389658764-39199-5-git-send-email-s-anna@ti.com> <52F92524.3080402@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org To: Ohad Ben-Cohen Cc: Bjorn Andersson , Mark Rutland , "devicetree@vger.kernel.org" , Suman Anna , Tony Lindgren , "linux-kernel@vger.kernel.org" , Grant Likely , Kumar Gala , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On Fri, Mar 14, 2014 at 03:12:26PM +0200, Ohad Ben-Cohen wrote: > On Sun, Mar 2, 2014 at 10:19 PM, Bjorn Andersson wrote: > > When introducing the ability to reference a hwspin lock via a phandle > > in device tree it makes a big difference to be able to differ between > > the case of "initialization failed" or "device not yet probed"; so > > that the client knows if it should fail or retry later. > > I'm not convinced. > > The only advantage this brings is to avoid retrying in case a fatal > error has occurred. Such fatal errors are extremely rare, and when > they show up - extremely painful, and I suspect that optimizing them > wouldn't be a big win. So, are you suggesting that because fatal errors should be "extremely rare", a consuming driver should just assume that if NULL is returned from a hwspin_lock_request*() function that it was the "device not yet probed" case that was hit? Note that having the consumer/hwspinlock device relationship modeled in devicetree introduces more potential failure cases... -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation