From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tero Kristo Subject: Re: [PATCH 0/3] ARM: OMAP2+: hwmod: RTC: Add lock and unlock hooks Date: Thu, 16 Jul 2015 10:09:23 +0300 Message-ID: <55A758A3.2070108@ti.com> References: <1433928386-24891-1-git-send-email-lokeshvutla@ti.com> <55A4DFEF.6040005@ti.com> <55A52208.5060302@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Paul Walmsley Cc: Lokesh Vutla , tony@atomide.com, linux-omap@vger.kernel.org, nsekhar@ti.com, linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org On 07/16/2015 03:15 AM, Paul Walmsley wrote: > On Tue, 14 Jul 2015, Tero Kristo wrote: > >> On 07/14/2015 01:09 PM, Lokesh Vutla wrote: >>> Hi, >>> On Wednesday 10 June 2015 02:56 PM, Lokesh Vutla wrote: >>>> Some IP blocks like RTC, needs an additional unlocking mechanism for >>>> writing to its registers. This patch adds optional lock and unlock >>>> function pointers to the IP block's hwmod data which gets executed >>>> before and after writing into IP sysconfig register. >>>> And also hook lock and unlock functions to AMx3xx, DRA7 RTC hwmod data, >>>> so that sysconfig registers are updated properly. >>> ping on this series. >>> >>> Thanks and regards, >>> Lokesh >> > > [...] > >> It is also racy, as there is no locking in place to avoid concurrent access to >> the lock/unlock registers across hwmod+driver. > > I don't see the race. Where is it? See drivers/rtc/rtc-omap.c, am3352_rtc_unlock and am3352_rtc_lock. That code is accessing the exact same registers. -Tero