Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8F0BC64EC4 for ; Fri, 3 Mar 2023 11:14:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230287AbjCCLOW (ORCPT ); Fri, 3 Mar 2023 06:14:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbjCCLOT (ORCPT ); Fri, 3 Mar 2023 06:14:19 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 140ED12076; Fri, 3 Mar 2023 03:14:12 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1F9792F4; Fri, 3 Mar 2023 03:14:55 -0800 (PST) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 193F83F93E; Fri, 3 Mar 2023 03:14:09 -0800 (PST) Date: Fri, 3 Mar 2023 11:14:07 +0000 From: Sudeep Holla To: "lihuisong (C)" Cc: robbiek@xsightlabs.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, rafael@kernel.org, rafael.j.wysocki@intel.com, wanghuiqiang@huawei.com, zhangzekun11@huawei.com, wangxiongfeng2@huawei.com, tanxiaofei@huawei.com, guohanjun@huawei.com, xiexiuqi@huawei.com, wangkefeng.wang@huawei.com, huangdaode@huawei.com Subject: Re: [PATCH 2/2] mailbox: pcc: Support shared interrupt for multiple subspaces Message-ID: <20230303111407.zdgqdwqik4spnq2o@bogus> References: <20221016034043.52227-1-lihuisong@huawei.com> <20230216063653.1995-1-lihuisong@huawei.com> <20230216063653.1995-3-lihuisong@huawei.com> <20230301133626.gchca3fdaqijxwzq@bogus> <2a165476-2e96-17b1-a50b-c8749462e8a1@huawei.com> <20230302140216.m4m3452vexyrnuln@bogus> <020cc964-9938-7ebe-7514-125cd041bfcb@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <020cc964-9938-7ebe-7514-125cd041bfcb@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 03, 2023 at 02:33:49PM +0800, lihuisong (C) wrote: > Sorry for my resend. Because I found that my last reply email is not in the > thread of this patch. I guess it may be send failed. > > 在 2023/3/2 22:02, Sudeep Holla 写道: > > No. I meant a comment saying it is not need since only one transfer can occur > > at a time and mailbox takes care of locking. So chan_in_use can be accessed > > without a lock. > Got it. Agreed. Thanks > > > For types no need this flag, it is always hard to understand and redundant > > > design. > > But does it matter ? You can even support shared interrupt for type 1&2. > BTW, type 1 subspaces do not support a level triggered platform interrupt as > no method is provided to clear the interrupt. Agreed but there is no harm using the flag, you can add a comment that it is useful only if shared interrupts are supported. That will imply it is dummy for type 1. I am avoiding too many type unnecessary checks especially in IRQ handler. > > They support level interrupt, so we can add them too. I understand you can > > test only type 3, but this driver caters for all and the code must be generic > > as much as possible. I don't see any point in check for type 3 only. Only > I understand what you do. > But type 2 also supports the communication flow from OSPM to Platfrom. > In this case, this flag will get in the way of type 2. > How ? > Whether the interrupt belongs to a type2 channel is only determined by > the status field in Generic Communications Channel Shared Memory Region, > which is done in rx_callback of PCC client. Agreed, but do you see any issue using the flag even if it acts as dummy ? -- Regards, Sudeep