Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1044746AbdDWKDq (ORCPT ); Sun, 23 Apr 2017 06:03:46 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:34348 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1044527AbdDWKDl (ORCPT ); Sun, 23 Apr 2017 06:03:41 -0400 MIME-Version: 1.0 In-Reply-To: <20170411124538.GB4973@arm.com> References: <1490809381-28869-1-git-send-email-jaswinder.singh@linaro.org> <64c77cc8-7327-d822-5976-c84b3d452ac5@arm.com> <20170406165806.GA27174@arm.com> <20170411124538.GB4973@arm.com> From: Jassi Brar Date: Sun, 23 Apr 2017 15:33:39 +0530 Message-ID: Subject: Re: [PATCH] mailbox: fix completion order for blocking requests To: Alexey Klimov Cc: Jassi Brar , Sudeep Holla , lkml Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2790 Lines: 67 On Tue, Apr 11, 2017 at 6:15 PM, Alexey Klimov wrote: > On Thu, Apr 06, 2017 at 10:45:26PM +0530, Jassi Brar wrote: >> On 6 April 2017 at 22:28, Alexey Klimov wrote: >> > Hi Jassi/Sudeep, >> > >> > On Wed, Mar 29, 2017 at 07:01:09PM +0100, Sudeep Holla wrote: >> >> >> >> >> >> On 29/03/17 18:43, Jassi Brar wrote: >> ... >> >> >> > diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c >> >> > index 9dfbf7e..e06c50c 100644 >> >> > --- a/drivers/mailbox/mailbox.c >> >> > +++ b/drivers/mailbox/mailbox.c >> >> > @@ -41,6 +41,7 @@ static int add_to_rbuf(struct mbox_chan *chan, void *mssg) >> >> > >> >> > idx = chan->msg_free; >> >> > chan->msg_data[idx] = mssg; >> >> > + init_completion(&chan->tx_cmpl[idx]); >> >> >> >> reinit would be better. >> > >> Of course. >> >> .... >> > From: Alexey Klimov >> > Date: Thu, 6 Apr 2017 13:57:02 +0100 >> > Subject: [RFC][PATCH] mailbox: per-channel arrays with msg data and completion >> > structures >> > >> > When a mailbox client doesn't serialize sending of the message itself, >> > and asks mailbox framework to block on mbox_send_message(), one >> > completion structure per channel is not enough. Client can make a few >> > mbox_send_message() calls at the same time, and there is no guaranteed >> > order of going to sleep on completion. >> > >> > If mailbox controller acks a message transfer, then tx_tick() wakes up >> > the first thread that waits on completion. >> > If mailbox controller doesn't ack the transfer and timeout happens, then >> > tx_tick() calls complete, and the next caller trying to sleep on >> > completion wakes up immediately. >> > >> > This patch fixes this by changing completion structures to be inserted >> > into an array that contains a) pointer to data provided by client and >> > b) the completion structure. Thus active_req field tracks the index of >> > the current running request that was submitted to mailbox controller. >> > >> > Signed-off-by: Alexey Klimov >> > --- >> > drivers/mailbox/mailbox.c | 40 +++++++++++++++++++++++--------------- >> > drivers/mailbox/pcc.c | 10 +++++++--- >> > include/linux/mailbox_controller.h | 24 +++++++++++++++++------ >> ... >> > 3 files changed, 49 insertions(+), 25 deletions(-) >> > >> Versus 4 files changed, 17 insertions(+), 8 deletions(-) >> >> I think we should just keep it simpler if it works just as fine. > > Along with this patch you still need at least one patch from Sudeep with subject: > "[PATCH 1/3] mailbox: always wait in mbox_send_message for blocking Tx mode" > Yes. Just so we are on same page, can you please redo your tests and see if this and Sudeep's patch-1/3 does the trick? Thanks