From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 716C8CD5BA4 for ; Thu, 21 May 2026 12:27:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=QKERNb/1FEYc0xDL9VQVwE6H1oVLPZS5L+kPq3cagjc=; b=zBq8LGRtObykJcVxlZ/txxbbaN N9Ftrf57F3kbEpkZX+ABcpaP/U9eirw4VwtLDzUYI9/bOCre7R0WnX7jNeo4D/GDg1zjjXSSaHzze V+hWF8IbuA47gV3kx8cfwWOqDMUXgZV5vojjzox7Uh2rJtKU0HO72PAzZvtLbErDH0wD86g7mOdxl f0tBnvN759OgRaHajMfzV4U3VrrkqbnX5TmCcu7kIL57LhrvsZGkgN/OoCo6b9IZHtwLSBZ/cGuTf YZ8N8AkEktWj9UODCSr6uZoiqmVnkdFJiD3aSB9yxLcIyK014ZvDI6R0Qdp4+xCF0Nqq+UMSfl160 P1FGf7Sg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQ2UT-00000007j2g-2MGC; Thu, 21 May 2026 12:27:05 +0000 Received: from canpmsgout10.his.huawei.com ([113.46.200.225]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQ2UQ-00000007j1f-0veX for linux-arm-kernel@lists.infradead.org; Thu, 21 May 2026 12:27:04 +0000 dkim-signature: v=1; a=rsa-sha256; d=h-partners.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=QKERNb/1FEYc0xDL9VQVwE6H1oVLPZS5L+kPq3cagjc=; b=m3qHm8hXl/pJT/hpA/XjXR08PRnsmfsipG6I8L3xnkYhWkIjgbj6XuBvAEl5WPrEmA3ryQan2 BYbqoEBbLbu4BiysZOq6yFUqUc6KES5WBxrZR6Ax7xfzTFNj7VdH3ySBQz3SPVldmeF9vJdobRV xJQuStX+gHBmrvBvxRd1Jjk= Received: from mail.maildlp.com (unknown [172.19.163.214]) by canpmsgout10.his.huawei.com (SkyGuard) with ESMTPS id 4gLnWs223Nz1K983; Thu, 21 May 2026 20:19:05 +0800 (CST) Received: from dggemv706-chm.china.huawei.com (unknown [10.3.19.33]) by mail.maildlp.com (Postfix) with ESMTPS id 09DE740561; Thu, 21 May 2026 20:26:46 +0800 (CST) Received: from kwepemn100009.china.huawei.com (7.202.194.112) by dggemv706-chm.china.huawei.com (10.3.19.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 21 May 2026 20:26:45 +0800 Received: from [10.67.121.59] (10.67.121.59) by kwepemn100009.china.huawei.com (7.202.194.112) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 21 May 2026 20:26:45 +0800 Message-ID: <9f7ab2db-d3cd-4ec0-97a1-38cf85696438@huawei.com> Date: Thu, 21 May 2026 20:26:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v02] mailbox: pcc: report errors for PCC clients To: Sudeep Holla CC: Adam Young , Jassi Brar , , , "Rafael J . Wysocki" , "Len Brown" , , Andi Shyti , Guenter Roeck , MyungJoo Ham , Kyungmin Park , Chanwoo Choi , References: <20260518193006.27425-1-admiyo@os.amperecomputing.com> <881ec4ba-44ce-498d-b0c4-8c1d51b13cc3@huawei.com> <20260519-outgoing-rough-fox-04daab@sudeepholla> <20260520-optimal-nightingale-of-champagne-0bbdfe@sudeepholla> From: "lihuisong (C)" In-Reply-To: <20260520-optimal-nightingale-of-champagne-0bbdfe@sudeepholla> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.121.59] X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemn100009.china.huawei.com (7.202.194.112) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260521_052703_297301_5DB1E0AB X-CRM114-Status: GOOD ( 29.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 5/20/2026 9:32 PM, Sudeep Holla wrote: > On Wed, May 20, 2026 at 07:53:45PM +0800, lihuisong (C) wrote: >> On 5/20/2026 12:25 AM, Sudeep Holla wrote: >>> On Tue, May 19, 2026 at 09:54:47PM +0800, lihuisong (C) wrote: > [...] > >>>> @Sudeep, I have always had doubts about the addition of this line of code in >>>> the >>>>  commit 9c753f7c953c (mailbox: pcc: Mark Tx as complete in PCC IRQ handler). >>>> The patch seems to avoid the timeouts in the mailbox core according to its >>>> commit log. >>>> Regardless of whether the command succeeds or fails, each mbox client >>>> driver, like cppc_acpi/acpi_pcc，kunpeng_hccs and so on, is responsible to >>>> call mbox_chan_txdone() to tell mailbox core. >>> Few controller drivers do have mbox_chan_txdone(), so Tx complete is detected >> Which controller driver? > git grep mbox_chan_txdone drivers/mailbox/ Ok > >>> by PCC, so not sure why you think this is not the right place to do. The irq >> Because many mbox client drivers call mbox_chan_txdone() after running >> rx_callback() in mbox_chan_received_data(). > OK, but why can't the controller hide that for the clients ? What am I missing? Now I know what you want to do. It's ok for me to do that in controller on irq scene. But we also need to fix the mbox_chan_txdone() code in all client drivers. > >> These drivers doesn't set chan->cl->tx_block to true. >> It seems that the client driver having tx_block need to set >> chan->tx_complete in tx_tick(). >> Do you add this code for them? > I don't quite follow you. please ship this. > >>> is to indicate the completion. I am confused as why you think otherwise. >>> It is defined in include/linux/mailbox_controller.h for the same reason. >>> >>> The client drivers can you mbox_client_txdone() if they wish to as defined >>> in include/linux/mailbox_client.h >> mbox_client_txdone() is used in the case that txdone_method is >> MBOX_TXDONE_BY_ACK. > Yes and agreed. > >> And mbox clinte driver using IRQ method need to use mbox_chan_txdone(). > Client doesn't handle IRQ its always controller driver and client must have > no business to do that IMO. Ack mbox_chan_txdone should be used by controller as this function comment said. > >> It seems that all the current client drivers are used in this way. >> These interface internal would verify chan->txdone_method. >> > Yes, sounds wrong to me. > > drivers/acpi/acpi_pcc.c > drivers/acpi/cppc_acpi.c > drivers/hwmon/xgene-hwmon.c > drivers/i2c/busses/i2c-xgene-slimpro.c > drivers/soc/hisilicon/kunpeng_hccs.c > > It is very clear from the code in mailbox.c, mbox_client_txdone() is for > the client drivers and mbox_chan_txdone() is for the controller. We need > to fix the above list but I need to check if there is anything I am missing > to understand first. Please let me know. Agreed. > >> In addition, I find that you also modify the txdone_irq/poll in the commit >> 3349f800609e (mailbox: pcc: Set txdone_irq/txdone_poll based on PCCT flags). >> The txdone_method will change from MBOX_TXDONE_BY_ACK to MBOX_TXDONE_BY_POLL >> on the platform using poll mode. >> This may lead to the original mbox client driver printing exceptions in >> mbox_client_txdone. >> I haven't observed it based on the latest code yet, it's just code analysis. > Right, I do remember seeing something and wonder if I moved to > mbox_chan_txdone() in drivers/acpi/acpi_pcc.c for that reason. But if the > expectations I have mentioned are correct, then we need to fix the framework > to avoid throwing that warnings. Yeah, we also need to do something for your another commit 3349f800609e (mailbox: pcc: Set txdone_irq/txdone_poll based on PCCT flags). >