From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752077AbbGaJwv (ORCPT ); Fri, 31 Jul 2015 05:52:51 -0400 Received: from foss.arm.com ([217.140.101.70]:44081 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950AbbGaJwu (ORCPT ); Fri, 31 Jul 2015 05:52:50 -0400 Message-ID: <55BB456F.4080400@arm.com> Date: Fri, 31 Jul 2015 10:52:47 +0100 From: Sudeep Holla User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Jassi Brar CC: Sudeep Holla , Linux Kernel Mailing List , Juri Lelli Subject: Re: [PATCH 1/2] mailbox: switch to hrtimer for tx_complete polling References: <1437568131-6398-1-git-send-email-sudeep.holla@arm.com> <55B1FBB6.9010803@arm.com> <55B5FE53.8020005@arm.com> <55B89342.4060700@arm.com> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/07/15 19:11, Jassi Brar wrote: > On Wed, Jul 29, 2015 at 2:18 PM, Sudeep Holla wrote: [..] >> >> Again, sorry for misleading comment, we do need hrtimer as replied on >> scpi thread. Any other concern with this patch ? >> > Polling by hrtimers is OK. Not to mean this is the best solution for > your platform. Please revise the changelog completely. > OK, how about: "The mailbox core uses jiffy based timer to handle polling for the transmit completion. If the client/protocol have/support notification of the last packet transmit completion via ACK packet, then we tick the Tx state machine immediately in the callback. However if the client doesn't support that mechanism we might end-up waiting for atleast a jiffy even though the remote is ready to receive the next request. This patch switches the timer used for that polling from jiffy-based to hrtimer-based so that we can support polling at much higher time resolution."