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 X-Spam-Level: X-Spam-Status: No, score=-11.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2D51C5CFFE for ; Mon, 10 Dec 2018 18:31:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B05122082F for ; Mon, 10 Dec 2018 18:31:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B05122082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728793AbeLJSbv (ORCPT ); Mon, 10 Dec 2018 13:31:51 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:60476 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726602AbeLJSbv (ORCPT ); Mon, 10 Dec 2018 13:31:51 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8C4D715BF; Mon, 10 Dec 2018 10:31:50 -0800 (PST) Received: from [10.1.194.37] (e113632-lin.cambridge.arm.com [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 77E8F3F6A8; Mon, 10 Dec 2018 10:31:49 -0800 (PST) Subject: Re: [PATCH v2] mailbox: Hi3660: Fixup mailbox state machine malfunction issue To: Kevin Wangtao , jassisinghbrar@gmail.com Cc: linux-kernel@vger.kernel.org, leo.yan@linaro.org, gengyanping@hisilicon.com, suzhuangluan@hisilicon.com References: <1543809309-61169-1-git-send-email-kevin.wangtao@hisilicon.com> <1543817588-82411-1-git-send-email-kevin.wangtao@hisilicon.com> From: Valentin Schneider Message-ID: Date: Mon, 10 Dec 2018 18:31:47 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <1543817588-82411-1-git-send-email-kevin.wangtao@hisilicon.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 03/12/2018 06:13, Kevin Wangtao wrote: > Current mailbox driver of Hi3660 release the mailbox directly > before sending a new message which may cause last message lost > and next message sending doesn't take effect actually. > > This patch fixes this issue by following the right process below, > each time before sending a message, mailbox driver will check > whether the mailbox is in ready state, if last message has been > acknowledged, mailbox driver will clear the ack state to turn > the mailbox to ready state again. > > Signed-off-by: Kevin Wangtao Validated using sysbench at each OPP ([1]). Test passes with patch and fails without: | CPU | OPP | Base | Patch | |------+---------+------+-------| | CPU0 | 533000 | 104 | 104 | | CPU0 | 999000 | 104 | 201 | | CPU0 | 140200 | 285 | 285 | | CPU0 | 1709000 | 285 | 349 | | CPU0 | 1844000 | 377 | 377 | |------+---------+------+-------| | CPU4 | 903000 | 249 | 248 | | CPU4 | 1421000 | 249 | 394 | | CPU4 | 1805000 | 500 | 500 | | CPU4 | 2112000 | 499 | 583 | | CPU4 | 2362000 | 653 | 654 | We need this pretty badly, otherwise frequency setting is a coin toss. Tested-by: Valentin Schneider Thanks, Valentin [1]: https://github.com/ARM-software/lisa/blob/next/lisa/tests/kernel/cpufreq/sanity.py#L23 Ran the above with this script on each kernel: ----->8----- #!/usr/bin/env python3 from lisa.env import TestEnv from lisa.tests.kernel.cpufreq.sanity import UserspaceSanity te = TestEnv.from_cli() print(UserspaceSanity.from_testenv(te).test_performance_sanity()) -----8<----- > --- > Changes v1 -> v2: > - update commit message > > drivers/mailbox/hi3660-mailbox.c | 22 ++++++++++------------ > 1 file changed, 10 insertions(+), 12 deletions(-) > > diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c > index 3eea6b6..035b71a 100644 > --- a/drivers/mailbox/hi3660-mailbox.c > +++ b/drivers/mailbox/hi3660-mailbox.c > @@ -38,6 +38,7 @@ > #define MBOX_AUTOMATIC_ACK 1 > > #define MBOX_STATE_IDLE BIT(4) > +#define MBOX_STATE_READY BIT(5) > #define MBOX_STATE_ACK BIT(7) > > #define MBOX_MSG_LEN 8 > @@ -91,8 +92,8 @@ static int hi3660_mbox_check_state(struct mbox_chan *chan) > unsigned long val; > unsigned int ret; > > - /* Mailbox is idle so directly bail out */ > - if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) > + /* Mailbox is ready to use */ > + if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY) > return 0; > > /* Wait for acknowledge from remote */ > @@ -103,9 +104,9 @@ static int hi3660_mbox_check_state(struct mbox_chan *chan) > return ret; > } > > - /* Ensure channel is released */ > - writel(0xffffffff, base + MBOX_IMASK_REG); > - writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG); > + /* clear ack state, mailbox will get back to ready state */ > + writel(BIT(mchan->ack_irq), base + MBOX_ICLR_REG); > + > return 0; > } > > @@ -160,10 +161,6 @@ static int hi3660_mbox_startup(struct mbox_chan *chan) > { > int ret; > > - ret = hi3660_mbox_check_state(chan); > - if (ret) > - return ret; > - > ret = hi3660_mbox_unlock(chan); > if (ret) > return ret; > @@ -183,10 +180,11 @@ static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg) > void __iomem *base = MBOX_BASE(mbox, ch); > u32 *buf = msg; > unsigned int i; > + int ret; > > - /* Ensure channel is released */ > - writel_relaxed(0xffffffff, base + MBOX_IMASK_REG); > - writel_relaxed(BIT(mchan->ack_irq), base + MBOX_SRC_REG); > + ret = hi3660_mbox_check_state(chan); > + if (ret) > + return ret; > > /* Clear mask for destination interrupt */ > writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG); >