Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754731AbaDRVPS (ORCPT ); Fri, 18 Apr 2014 17:15:18 -0400 Received: from mail-ve0-f172.google.com ([209.85.128.172]:53793 "EHLO mail-ve0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754645AbaDRVPK (ORCPT ); Fri, 18 Apr 2014 17:15:10 -0400 MIME-Version: 1.0 In-Reply-To: References: <1397757570-19750-1-git-send-email-dianders@chromium.org> <1397757570-19750-3-git-send-email-dianders@chromium.org> Date: Fri, 18 Apr 2014 14:15:09 -0700 X-Google-Sender-Auth: yNKkrOSIYjXREpHX_HMey--iRIU Message-ID: Subject: Re: [PATCH 2/7] mfd: cros_ec: spi: Add mutex to cros_ec_spi From: Doug Anderson To: Simon Glass Cc: Lee Jones , Stephen Warren , Wolfram Sang , Andrew Bresticker , Dylan Reid , Olof Johansson , linux-samsung-soc , "linux-tegra@vger.kernel.org" , Samuel Ortiz , lk Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Simon, On Fri, Apr 18, 2014 at 10:28 AM, Simon Glass wrote: > Hi Doug, > > On 17 April 2014 11:59, Doug Anderson wrote: >> The main transfer function for cros_ec_spi can be called by more than >> one client at a time. Make sure that those clients don't stomp on >> each other by locking the bus for the duration of the transfer >> function. > > Is there no lock at the cros_ec layer? Not with what's upstream. Locally in the Chromium OS tree: * You can see that Bill removed the dev_lock at since it wasn't used. * Andrew moved to a common locking scheme later in (thus adding roughly the same lock back and using it), but in order to do that we've got a dozen pathces in between, some of which are big reorganizations. This includes at least: 6820b91 CHROMIUM: cros_ec: Tweak struct cros_ec_device for clarity 5e8e562 CHROMIUM: Use struct cros_ec_command to communicate with the EC 9e7db82 CHROMIUM: cleanup: remove unused fields from struct cros_ec_device 866e62d CHROMIUM: cleanup: Remove EC wrapper functions. 8a372b2 cros_ec: move locking into cros_ec_cmd_xfer 981c4aa cros_ec: stop calling ->cmd_xfer() directly I think we should take in some of those other changes but I'd rather get correctness in first (since people are wanting to use this driver in upstream kernel) and get cleanups posted after this lands. I was also trying not to spam the list with a 20-patch series... -Doug -- 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/