From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:23204 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752544Ab0DSTLU (ORCPT ); Mon, 19 Apr 2010 15:11:20 -0400 Subject: Re: [PATCH 5/5] arm: msm: smd: fix SMD modem processor sync condition From: Daniel Walker In-Reply-To: References: <1271700189-8376-5-git-send-email-dwalker@codeaurora.org> <1271703705.15004.4.camel@c-dwalke-linux.qualcomm.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 19 Apr 2010 12:11:17 -0700 Message-ID: <1271704277.15004.8.camel@c-dwalke-linux.qualcomm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arm-msm-owner@vger.kernel.org List-ID: To: Dima Zavin Cc: linux-arm-msm@vger.kernel.org On Mon, 2010-04-19 at 12:06 -0700, Dima Zavin wrote: > On Mon, Apr 19, 2010 at 12:01 PM, Daniel Walker wrote: > > On Mon, 2010-04-19 at 11:34 -0700, Dima Zavin wrote: > >> Do we really need a formalized blocking point here? The apps processor > >> can do other useful initialization work while the modem is booting. > >> The first time you do a proc_comm call, it checks the PCOM_READY > >> state, and will block anyway. Preventing the apps processor from > >> continuing until then is suboptimal. If there are bugs in the modem > >> code where it incorrectly stomps on shared resources, then those > >> should be fixed. This patch looks like a hack to me. > > > > > > Yes, we need to formalize a blocking point .. The apps processor waits > > in this way no matter what you do .. Like your saying above "The first > > time you do a proc_comm call, it checks the PCOM_READY state, and will > > block anyway" that's a hack .. What your saying is _maybe_ there exists > > a proc_comm call early enough to prevent a crash, or maybe not .. That's > > not formal enough. > > That's not at all what I am saying. There's no maybe. If I don't need > anything from the modem, I won't make a proc_comm call. If there is a > crash because the modem is modifying shared resources that affect the > apps processor without an appropriate synchronization point, then it's > a bug on the modem side. Making this change will only mask modem bugs. If you don't make a proc_call call SMD won't initialize properly early on, since the modem may or may not be booted far enough to accept input over SMD.. Then you can basically have a failed SMD init, which means you crash when you actually need stuff through SMD. Daniel