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 9DED3C35274 for ; Mon, 18 Dec 2023 23:03:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:Cc:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=r9L1hwLjHr+KANCVDDzFC9EBI2IiMvAWffQ/PPosPSo=; b=3u6brwTkHqPHPz 8YTu1rTRBpUgCqs7d+JPkEY6mPSQioUfUEgMQqPETT9KMs8cNwIhkIBNJN4CpMHflFI3zOHtXTX4u lSBxQlvG3tJCEsnIx66gbFaw8BL802Tm/2qFs3E3zsp/nsXsFpRwmAJiFNin9qFzw85qX3uEAayoN sSPD2jeFCv6XFcVCX7Z+i0ZSt5BG4pgaNFMq4mh+iBXGEIo+HCT0hSvnECsPahcWHPKJjbGe6btgi 8DFVNFyrEjuxvMgnb5f8u7IcuHtEQXLWCJdZXfvSw7d13dJhvGS5fKVWPs4K4cuQa1NRPSKqB17PM SOVLxvaewVgwku6Dc4UA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rFMdc-00CHp4-1d; Mon, 18 Dec 2023 23:03:04 +0000 Received: from pi.codeconstruct.com.au ([203.29.241.158] helo=codeconstruct.com.au) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rFMdZ-00CHoE-1L for linux-arm-kernel@lists.infradead.org; Mon, 18 Dec 2023 23:03:03 +0000 Received: from [192.168.68.112] (ppp118-210-80-147.adl-adc-lon-bras32.tpg.internode.on.net [118.210.80.147]) by mail.codeconstruct.com.au (Postfix) with ESMTPSA id 0D8F72014F; Tue, 19 Dec 2023 07:02:47 +0800 (AWST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codeconstruct.com.au; s=2022a; t=1702940572; bh=YJxqecOL6R6o6l2AGHwi7QgNX0u29B+GDnVZRFgkI+k=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=WPpwQ9xuCxjzJXTUKiuwMsoVkjUOhqrT6gnnb+LZcvdi72ZyLxsdejy13T3hs6sJn jec0d5Yk7/2oi6H9++Tf2QiyR2h/vHmi1wIH91bYIFfcc9CVWxGyIlJswVcVgmvrdG aQHnrOaw1d9VThcRuYhLTvTqr1q2qch4DLthL4XtR1PqjhgVw5TWULqAKdTkUc14mg vJjWfXN1VFaLe6mLftYRcg2sz8Kpue0Z4pU6DtLCkYRXKq9Yc8hBsQaWwQXfZzUlae Zz9md12KBZIi1UpqHb7lMHQA9Zl/6UKbC2FOyGuxuWTZjkk1LkZ/Nyx9j70mgR/Bgk htzkxxHW79TMQ== Message-ID: <477f1e8fbed91cc1160086af1f20030e7a6d853b.camel@codeconstruct.com.au> Subject: Re: [PATCH v4 2/2] i2c: aspeed: Acknowledge Tx done with and without ACK irq late From: Andrew Jeffery To: Quan Nguyen , Brendan Higgins , Benjamin Herrenschmidt , Joel Stanley , Andi Shyti , Wolfram Sang , Jae Hyun Yoo , Guenter Roeck , linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Cosmo Chou , Open Source Submission , Phong Vo , "Thang Q . Nguyen" Date: Tue, 19 Dec 2023 09:32:45 +1030 In-Reply-To: <7dfc99e5-4c76-413b-aabc-81b26e26249e@os.amperecomputing.com> References: <20231211102217.2436294-1-quan@os.amperecomputing.com> <20231211102217.2436294-3-quan@os.amperecomputing.com> <2eab42cde34723a195e7a0287db08b25f8388a3b.camel@codeconstruct.com.au> <54cba87a0df233b8762e43b742afe8e44a77a60c.camel@codeconstruct.com.au> <7dfc99e5-4c76-413b-aabc-81b26e26249e@os.amperecomputing.com> User-Agent: Evolution 3.46.4-2 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231218_150301_883924_32DBB25A X-CRM114-Status: GOOD ( 16.79 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 2023-12-18 at 15:45 +0700, Quan Nguyen wrote: > > On 15/12/2023 05:21, Andrew Jeffery wrote: > > > > ``` > > $ qemu-system-arm \ > > -M ast2600-evb \ > > -kernel build.aspeed_g5/arch/arm/boot/zImage \ > > -dtb build.aspeed_g5/arch/arm/boot/dts/aspeed/aspeed-ast2600-evb.dtb \ > > -initrd ~/src/buildroot.org/buildroot/output/images/rootfs.cpio.xz \ > > -nographic 2>&1 \ > > | ts -s > > ... > > 00:00:03 [ 1.089187] Freeing initrd memory: 3308K > > 00:00:05 smbus: error: Unexpected send start condition in state 1 > > 00:00:05 smbus: error: Unexpected write in state -1 > > 00:00:06 [ 3.685731] aspeed-i2c-bus 1e78a400.i2c-bus: i2c bus 7 registered, irq 48 > > 00:00:06 [ 3.688918] aspeed-i2c-bus 1e78a480.i2c-bus: i2c bus 8 registered, irq 49 > > 00:00:06 [ 3.692326] aspeed-i2c-bus 1e78a500.i2c-bus: i2c bus 9 registered, irq 50 > > 00:00:06 [ 3.693757] aspeed-i2c-bus 1e78a680.i2c-bus: i2c bus 12 registered, irq 51 > > 00:00:06 [ 3.695070] aspeed-i2c-bus 1e78a700.i2c-bus: i2c bus 13 registered, irq 52 > > 00:00:06 [ 3.696184] aspeed-i2c-bus 1e78a780.i2c-bus: i2c bus 14 registered, irq 53 > > 00:00:06 [ 3.697144] aspeed-i2c-bus 1e78a800.i2c-bus: i2c bus 15 registered, irq 54 > > 00:00:06 [ 3.699061] aspeed-video 1e700000.video: irq 55 > > 00:00:06 [ 3.699254] aspeed-video 1e700000.video: assigned reserved memory node video > > 00:00:06 [ 3.702755] aspeed-video 1e700000.video: alloc mem size(24576) at 0xbc000000 for jpeg header > > 00:00:06 [ 3.706139] Driver for 1-wire Dallas network protocol. > > 00:00:07 smbus: error: Unexpected send start condition in state -1 > > 00:00:07 smbus: error: Unexpected write in state -1 > > 00:00:10 smbus: error: Unexpected send start condition in state -1 > > 00:00:10 smbus: error: Unexpected write in state -1 > > 00:00:12 smbus: error: Unexpected send start condition in state -1 > > 00:00:12 smbus: error: Unexpected write in state -1 > > 00:00:14 smbus: error: Unexpected send start condition in state -1 > > 00:00:14 smbus: error: Unexpected write in state -1 > > 00:00:17 smbus: error: Unexpected send start condition in state -1 > > 00:00:17 smbus: error: Unexpected write in state -1 > > 00:00:18 [ 14.080141] adt7475 7-002e: Error configuring attenuator bypass > > 00:00:19 smbus: error: Unexpected send start condition in state -1 > > 00:00:19 smbus: error: Unexpected write in state -1 > > 00:00:21 smbus: error: Unexpected send start condition in state -1 > > 00:00:21 smbus: error: Unexpected write in state -1 > > 00:00:24 smbus: error: Unexpected send start condition in state -1 > > 00:00:24 smbus: error: Unexpected write in state -1 > > ``` > > > > The smbus errors do not occur if I revert this patch. > > > > Can you look into qemu to see if it's a bug in the aspeed i2c > > controller model's state machine? > > > > Thanks, Andrew, for testing these patches on qemu. > > I'll try to look into it to see if anything can be improved, but I have > to admit that I'm not so familiar with it. This is my first time trying > it on qemu. Just did these tests on real HW with waveform captured > sometimes. > > So far I could be able to reproduce the issue and start playing around > trying to understand the model. > So `$ git grep -lF 'Unexpected write in state'` leads us to hw/i2c/smbus_slave.c:193. From the switch statement there and the log output above dev->mode must be SMBUS_CONFUSED: https://gitlab.com/qemu-project/qemu/-/blob/039afc5ef7367fbc8fb475580c291c2655e856cb/hw/i2c/smbus_slave.c#L35-L41 The prior log message was: ``` 00:00:05 smbus: error: Unexpected send start condition in state 1 ``` So we entered SMBUS_CONFUSED from SMBUS_WRITE_DATA. Given the log output above it suggests the master model is failing to send an I2C_FINISH prior to I2C_START_SEND, as that log message is emitted from `dev->mode != SMBUS_IDLE` when the slave sees an `I2C_START_SEND`. Perhaps the M_STOP_CMD handling needs to go above the M_START_CMD handling in aspeed_i2c_bus_handle_cmd()? https://gitlab.com/qemu-project/qemu/-/blob/039afc5ef7367fbc8fb475580c291c2655e856cb/hw/i2c/aspeed_i2c.c#L450 Andrew _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel