From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Sakkinen Subject: Re: [PATCH] tpm: drop chip->is_open and chip->duration_adjusted Date: Mon, 14 Nov 2016 21:11:54 -0800 Message-ID: <20161115051106.u2xoduwf2kpcznv3@intel.com> References: <20161114234500.24839-1-jarkko.sakkinen@linux.intel.com> <20161115043001.GA22482@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20161115043001.GA22482-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tpmdd-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Jason Gunthorpe Cc: Christophe Ricard , open list , linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: tpmdd-devel@lists.sourceforge.net On Mon, Nov 14, 2016 at 09:30:01PM -0700, Jason Gunthorpe wrote: > On Mon, Nov 14, 2016 at 03:44:58PM -0800, Jarkko Sakkinen wrote: > > Use atomic bitops for chip->flags so that we do not need chip->is_open > > and chip->duration_adjusted anymore. > > I don't know if it s a really great idea to use atomic bit ops for > things that do not need to be atomic.. It makes the locking scheme > less clear. is open is genuinely different since it relies on the > atomic for correctness. The way I see it is one of the status flags bound to chip among the others. I do not see this cause too much harm for clarity. It eases debugging the driver a bit because you get more state out of 'flags'. It also makes code little a bit more robust as flags is independent of locks. How strong is your opposition here? I do not see any exceptional damage done but see some subtle but still significant benefits. > Merging is_duration makes lots of sense though Also timeout_adjusted should be merged (for some reason missed it). > Jason /Jarkko ------------------------------------------------------------------------------