From patchwork Tue Oct 20 08:33:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Wu X-Patchwork-Id: 293591 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=-12.7 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 70915C433DF for ; Tue, 20 Oct 2020 08:34:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C28F62225F for ; Tue, 20 Oct 2020 08:34:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=vivotek.com header.i=@vivotek.com header.b="I79hXsWA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389000AbgJTIeW (ORCPT ); Tue, 20 Oct 2020 04:34:22 -0400 Received: from mail.vivotek.com ([60.248.39.150]:45716 "EHLO mail.vivotek.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727228AbgJTIeV (ORCPT ); Tue, 20 Oct 2020 04:34:21 -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 09K8Xx5j028535; Tue, 20 Oct 2020 16:34:14 +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=OiryTol3lsa7n+iIcBzbc/EuEG5m0GVQYbD/SFQ9KYU=; b=I79hXsWAP5jvfi9upAnYpnG8SSj/JmsBA1UZhmGJaLYET9mVJi+vZziiHAkqqgj3B9pK 2FY1dM192RzxpFjzYYwz7NAMduW9oOc0lmmQb6sP8CtW5IuayDG4xvvX4Op7yn9jI3Jn 1+X8YeBTpER542Pnp+gpS6eo6idILuISp3o= Received: from cas01.vivotek.tw ([192.168.0.58]) by vivotekpps.vivotek.com with ESMTP id 349m9fg9d4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Tue, 20 Oct 2020 16:34:14 +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; Tue, 20 Oct 2020 16:34:13 +0800 From: Michael Wu To: Jarkko Nikula , Andy Shevchenko , Mika Westerberg , , CC: Morgan Chang , Michael Wu Subject: [PATCH] i2c: designware: call i2c_dw_read_clear_intrbits_slave() once Date: Tue, 20 Oct 2020 16:33:10 +0800 Message-ID: <20201020083310.7489-1-michael.wu@vatics.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [192.168.17.134] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-10-20_04:2020-10-20,2020-10-20 signatures=0 X-Proofpoint-Spam-Reason: safe Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org i2c_dw_read_clear_intrbits_slave() was called per each interrupt handle. It caused some interrupt bits which haven't been handled yet were cleared, the corresponding handlers would do nothing due to interrupt bits been discarded. For example, $ 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. The root cause is that i2c_dw_read_clear_intrbits_slave() was called many times. Calling i2c_dw_read_clear_intrbits_slave() once in one ISR and take the returned stat for later handling is the solution. Signed-off-by: Michael Wu --- drivers/i2c/busses/i2c-designware-slave.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c index 44974b53a626..02e7c5171827 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); @@ -168,13 +167,11 @@ 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_RD_REQ) { if (slave_activity) { if (stat & DW_IC_INTR_RX_FULL) { @@ -188,11 +185,9 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) 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, @@ -207,7 +202,6 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp); i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); - stat = i2c_dw_read_clear_intrbits_slave(dev); return 1; } @@ -217,10 +211,11 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED, &val)) dev_vdbg(dev->dev, "Byte %X acked!", val); - } else { + } else i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); - stat = i2c_dw_read_clear_intrbits_slave(dev); - } + + if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET)) + i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val); return 1; } @@ -230,7 +225,6 @@ 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);