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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 27660C433E7 for ; Wed, 14 Oct 2020 05:26:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2CF522227 for ; Wed, 14 Oct 2020 05:26:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=vivotek.com header.i=@vivotek.com header.b="EBkxsn13" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728815AbgJNF0u (ORCPT ); Wed, 14 Oct 2020 01:26:50 -0400 Received: from mail.vivotek.com ([60.248.39.150]:47348 "EHLO mail.vivotek.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728619AbgJNF0u (ORCPT ); Wed, 14 Oct 2020 01:26:50 -0400 Received: from pps.filterd (vivotekpps.vivotek.com [127.0.0.1]) by vivotekpps.vivotek.com (8.16.0.42/8.16.0.42) with SMTP id 09E5PEBT029712; Wed, 14 Oct 2020 13:26:43 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vivotek.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=dkim; bh=vgyu/BhhyrWEekZhbBTnSbUBvL3B5Y+saUl7LForRJw=; b=EBkxsn13pBWELWU9d4jgB6uUDkM6r+iMEasd1xyFVKSsY+MQI8FdjRWrtzt7ct7qojo4 hK98w8R3MQL0N+vYxcm4t6yWjHaBvY25VF2fGqSCs8tWwIQ/iUVpz2Mb+cHO9iSPi5NY oCGX4pXTlxaZzB6a4zykbStuuDomATyZrPU= Received: from cas01.vivotek.tw ([192.168.0.58]) by vivotekpps.vivotek.com with ESMTP id 342yd1ans1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Wed, 14 Oct 2020 13:26:43 +0800 Received: from localhost.localdomain (192.168.17.134) by CAS01.vivotek.tw (192.168.0.58) with Microsoft SMTP Server (TLS) id 14.3.487.0; Wed, 14 Oct 2020 13:26:42 +0800 From: Michael Wu To: Jarkko Nikula , Andy Shevchenko , Mika Westerberg , , CC: Morgan Chang , Dean Hsiao , Paul Chen , Michael Wu Subject: [PATCH] i2c: designware: fix slave omitted IC_INTR_STOP_DET Date: Wed, 14 Oct 2020 13:25:32 +0800 Message-ID: <20201014052532.3298-1-michael.wu@vatics.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [192.168.17.134] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-10-14_03:2020-10-14,2020-10-14 signatures=0 X-Proofpoint-Spam-Reason: safe Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org When an I2C slave works, sometimes both IC_INTR_RX_FULL and IC_INTR_STOP_DET are rising during an IRQ handle, especially when system is busy or too late to handle interrupts. If IC_INTR_RX_FULL is rising and the system doesn't handle immediately, IC_INTR_STOP_DET may be rising and the system has to handle these two events. For this there may be two problems: 1. IC_INTR_STOP_DET is rising after i2c_dw_read_clear_intrbits_slave() done: It seems invalidated because WRITE_REQUESTED is done after the 1st WRITE_RECEIVED. $ i2cset -f -y 2 0x42 0x00 0x41; dmesg -c [0][clear_intrbits]0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 [1][irq_handler ]0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 WRITE_RECEIVED [0][clear_intrbits]0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 [1][irq_handler ]0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204 WRITE_REQUESTED WRITE_RECEIVED [0][clear_intrbits]0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x710 : INTR_STAT=0x200 [1][irq_handler ]0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x510 : INTR_STAT=0x0 STOP [2][clear_intrbits]0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x510 : INTR_STAT=0x0 t1: ISR with the 1st IC_INTR_RX_FULL. t2: Clear listed IC_INTR bits by i2c_dw_read_clear_intrbits_slave(). t3: Enter i2c_dw_irq_handler_slave() and then do i2c_slave_event(WRITE_RECEIVED) because if (stat & DW_IC_INTR_RX_FULL). t4: ISR with the 2nd IC_INTR_RX_FULL. t5: Clear listed IC_INTR bits by i2c_dw_read_clear_intrbits_slave(), while IC_INTR_STOP_DET has not risen yet. t6: Enter i2c_dw_irq_handler_slave() and then IC_INTR_STOP_DET is rising. i2c_slave_event(WRITE_REQUESTED) will be done first because if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET)) and then doing i2c_slave_event(WRITE_RECEIVED). t7: do i2c_slave_event(STOP) due to IC_INTR_STOP_DET not be cleared yet. 2. Both IC_INTR_STOP_DET and IC_INTR_RX_FULL are rising before i2c_dw_read_clear_intrbits_slave(): STOP cannot wait because IC_INTR_STOP_DET is cleared by i2c_dw_read_clear_intrbits_slave(). $ i2cset -f -y 2 0x42 0x00 0x41; dmesg -c [0][clear_intrbits]0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 [1][irq_handler ]0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 WRITE_RECEIVED [0][clear_intrbits]0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204 [1][irq_handler ]0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 WRITE_RECEIVED t1: ISR with the 1st IC_INTR_RX_FULL. t2: Clear listed IC_INTR bits by i2c_dw_read_clear_intrbits_slave(). t3: Enter i2c_dw_irq_handler_slave() and then do i2c_slave_event(WRITE_RECEIVED) because if (stat & DW_IC_INTR_RX_FULL). t4: ISR with both IC_INTR_STOP_DET and the 2nd IC_INTR_RX_FULL. t5: Clear listed IC_INTR bits by i2c_dw_read_clear_intrbits_slave(). The current IC_INTR_STOP_DET is cleared by this i2c_dw_read_clear_intrbits_slave(). t6: Enter i2c_dw_irq_handler_slave() and then do i2c_slave_event(WRITE_RECEIVED) because if (stat & DW_IC_INTR_RX_FULL). t7: i2c_slave_event(STOP) never be done because IC_INTR_STOP_DET was cleared in t5. In order to resolve these problems, i2c_dw_read_clear_intrbits_slave() should be called only one time in ISR and take the returned stat to handle those occurred events. Signed-off-by: Michael Wu --- drivers/i2c/busses/i2c-designware-slave.c | 79 ++++++++++++----------- 1 file changed, 40 insertions(+), 39 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c index 44974b53a626..8b3047fb2eae 100644 --- a/drivers/i2c/busses/i2c-designware-slave.c +++ b/drivers/i2c/busses/i2c-designware-slave.c @@ -159,7 +159,6 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) u32 raw_stat, stat, enabled, tmp; u8 val = 0, slave_activity; - regmap_read(dev->map, DW_IC_INTR_STAT, &stat); regmap_read(dev->map, DW_IC_ENABLE, &enabled); regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_stat); regmap_read(dev->map, DW_IC_STATUS, &tmp); @@ -168,58 +167,61 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY) || !dev->slave) return 0; + stat = i2c_dw_read_clear_intrbits_slave(dev); dev_dbg(dev->dev, "%#x STATUS SLAVE_ACTIVITY=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n", enabled, slave_activity, raw_stat, stat); - if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET)) - i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val); + if (stat & DW_IC_INTR_RX_FULL) { + if (dev->status != STATUS_WRITE_IN_PROGRESS) { + if (dev->status != STATUS_IDLE) + i2c_slave_event(dev->slave, I2C_SLAVE_STOP, + &val); + + dev->status = STATUS_WRITE_IN_PROGRESS + i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, + &val); + } + + regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); + val = tmp; + + if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED, + &val)) + dev_vdbg(dev->dev, "Byte %X acked!", val); + } if (stat & DW_IC_INTR_RD_REQ) { + if (dev->status != STATUS_IDEL) { + dev->status = STATUS_IDLE; + i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); + } + if (slave_activity) { - if (stat & DW_IC_INTR_RX_FULL) { - regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); - val = tmp; - - if (!i2c_slave_event(dev->slave, - I2C_SLAVE_WRITE_RECEIVED, - &val)) { - dev_vdbg(dev->dev, "Byte %X acked!", - val); - } - regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp); - stat = i2c_dw_read_clear_intrbits_slave(dev); - } else { - regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp); - regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp); - stat = i2c_dw_read_clear_intrbits_slave(dev); - } - if (!i2c_slave_event(dev->slave, - I2C_SLAVE_READ_REQUESTED, - &val)) - regmap_write(dev->map, DW_IC_DATA_CMD, val); + regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp); + regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp); + + dev->status = STATUS_READ_IN_PROGRESS; + i2c_slave_event(dev->slave, I2C_SLAVE_READ_REQUESTED, + &val); + regmap_write(dev->map, DW_IC_DATA_CMD, val); } } if (stat & DW_IC_INTR_RX_DONE) { - if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED, - &val)) - regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp); + i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED, &val); + regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp); + dev->status = STATUS_IDLE; i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); - stat = i2c_dw_read_clear_intrbits_slave(dev); - return 1; } - if (stat & DW_IC_INTR_RX_FULL) { - regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); - val = tmp; - if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED, - &val)) - dev_vdbg(dev->dev, "Byte %X acked!", val); - } else { - i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); - stat = i2c_dw_read_clear_intrbits_slave(dev); + if (stat & DW_IC_INTR_STOP_DET) { + if (dev->status != STATUS_IDLE) { + dev->status = STATUS_IDLE; + + i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); + } } return 1; @@ -230,7 +232,6 @@ static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id) struct dw_i2c_dev *dev = dev_id; int ret; - i2c_dw_read_clear_intrbits_slave(dev); ret = i2c_dw_irq_handler_slave(dev); if (ret > 0) complete(&dev->cmd_complete); -- 2.17.1