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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 BA989ECDFB8 for ; Mon, 23 Jul 2018 18:10:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 658FA20852 for ; Mon, 23 Jul 2018 18:10:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 658FA20852 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.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 S2388272AbeGWTM2 (ORCPT ); Mon, 23 Jul 2018 15:12:28 -0400 Received: from mga17.intel.com ([192.55.52.151]:9334 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387861AbeGWTM2 (ORCPT ); Mon, 23 Jul 2018 15:12:28 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Jul 2018 11:10:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,394,1526367600"; d="scan'208";a="75216521" Received: from skyhawk.jf.intel.com (HELO [10.7.150.62]) ([10.7.150.62]) by orsmga001.jf.intel.com with ESMTP; 23 Jul 2018 11:10:03 -0700 Subject: Re: [PATCH i2c-next] i2c: aspeed: Handle master/slave combined irq events properly To: Jae Hyun Yoo , Brendan Higgins , Benjamin Herrenschmidt , Joel Stanley , Andrew Jeffery , 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: Vernon Mauery , Jarkko Nikula References: <20180723174808.4007-1-jae.hyun.yoo@linux.intel.com> From: James Feist Message-ID: <58d31319-83c0-969b-e3fd-4273818929fc@linux.intel.com> Date: Mon, 23 Jul 2018 11:10:03 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180723174808.4007-1-jae.hyun.yoo@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/23/2018 10:48 AM, Jae Hyun Yoo wrote: > In most of cases, interrupt bits are set one by one but there are > also a lot of other cases that Aspeed I2C IP sends multiple > interrupt bits with combining master and slave events using a > single interrupt call. It happens much in multi-master environment much more > than single-master. For an example, when master is waiting for a > NORMAL_STOP interrupt in its MASTER_STOP state, SLAVE_MATCH and > RX_DONE interrupts could come along with the NORMAL_STOP in case of > an another master immediately sends data just after acquiring the > bus. In this case, the NORMAL_STOP interrupt should be handled > by master_irq and the SLAVE_MATCH and RX_DONE interrupts should be > handled by slave_irq. This commit modifies irq hadling logic to > handle the master/slave combined events properly. > > Signed-off-by: Jae Hyun Yoo > --- > drivers/i2c/busses/i2c-aspeed.c | 137 ++++++++++++++++++-------------- > 1 file changed, 76 insertions(+), 61 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c > index efb89422d496..24d43f143a55 100644 > --- a/drivers/i2c/busses/i2c-aspeed.c > +++ b/drivers/i2c/busses/i2c-aspeed.c > @@ -82,6 +82,11 @@ > #define ASPEED_I2CD_INTR_RX_DONE BIT(2) > #define ASPEED_I2CD_INTR_TX_NAK BIT(1) > #define ASPEED_I2CD_INTR_TX_ACK BIT(0) > +#define ASPEED_I2CD_INTR_ERRORS \ > + (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT | \ > + ASPEED_I2CD_INTR_SCL_TIMEOUT | \ > + ASPEED_I2CD_INTR_ABNORMAL | \ > + ASPEED_I2CD_INTR_ARBIT_LOSS) > #define ASPEED_I2CD_INTR_ALL \ > (ASPEED_I2CD_INTR_SDA_DL_TIMEOUT | \ > ASPEED_I2CD_INTR_BUS_RECOVER_DONE | \ > @@ -150,6 +155,7 @@ struct aspeed_i2c_bus { > int cmd_err; > /* Protected only by i2c_lock_bus */ > int master_xfer_result; > + u32 irq_status; > #if IS_ENABLED(CONFIG_I2C_SLAVE) > struct i2c_client *slave; > enum aspeed_i2c_slave_state slave_state; > @@ -229,36 +235,30 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus) > #if IS_ENABLED(CONFIG_I2C_SLAVE) > static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) > { > - u32 command, irq_status, status_ack = 0; > + u32 command, status_ack = 0; > struct i2c_client *slave = bus->slave; > - bool irq_handled = true; > u8 value; > > - if (!slave) { > - irq_handled = false; > - goto out; > - } > + if (!slave) > + return false; > > command = readl(bus->base + ASPEED_I2C_CMD_REG); > - irq_status = readl(bus->base + ASPEED_I2C_INTR_STS_REG); > > /* Slave was requested, restart state machine. */ > - if (irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) { > + if (bus->irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) { > status_ack |= ASPEED_I2CD_INTR_SLAVE_MATCH; > bus->slave_state = ASPEED_I2C_SLAVE_START; > } > > /* Slave is not currently active, irq was for someone else. */ > - if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) { > - irq_handled = false; > - goto out; > - } > + if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) > + return false; > > dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", > - irq_status, command); > + bus->irq_status, command); > > /* Slave was sent something. */ > - if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { > + if (bus->irq_status & ASPEED_I2CD_INTR_RX_DONE) { > value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; > /* Handle address frame. */ > if (bus->slave_state == ASPEED_I2C_SLAVE_START) { > @@ -273,28 +273,29 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) > } > > /* Slave was asked to stop. */ > - if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { > + if (bus->irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { > status_ack |= ASPEED_I2CD_INTR_NORMAL_STOP; > bus->slave_state = ASPEED_I2C_SLAVE_STOP; > } > - if (irq_status & ASPEED_I2CD_INTR_TX_NAK) { > + if (bus->irq_status & ASPEED_I2CD_INTR_TX_NAK) { > status_ack |= ASPEED_I2CD_INTR_TX_NAK; > bus->slave_state = ASPEED_I2C_SLAVE_STOP; > } > + if (bus->irq_status & ASPEED_I2CD_INTR_TX_ACK) { > + status_ack |= ASPEED_I2CD_INTR_TX_ACK; > + } > > switch (bus->slave_state) { > case ASPEED_I2C_SLAVE_READ_REQUESTED: > - if (irq_status & ASPEED_I2CD_INTR_TX_ACK) > + if (bus->irq_status & ASPEED_I2CD_INTR_TX_ACK) > dev_err(bus->dev, "Unexpected ACK on read request.\n"); > bus->slave_state = ASPEED_I2C_SLAVE_READ_PROCESSED; > - > i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value); > writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG); > writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); > break; > case ASPEED_I2C_SLAVE_READ_PROCESSED: > - status_ack |= ASPEED_I2CD_INTR_TX_ACK; > - if (!(irq_status & ASPEED_I2CD_INTR_TX_ACK)) > + if (!(bus->irq_status & ASPEED_I2CD_INTR_TX_ACK)) > dev_err(bus->dev, > "Expected ACK after processed read.\n"); > i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value); > @@ -317,14 +318,8 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) > break; > } > > - if (status_ack != irq_status) > - dev_err(bus->dev, > - "irq handled != irq. expected %x, but was %x\n", > - irq_status, status_ack); > - writel(status_ack, bus->base + ASPEED_I2C_INTR_STS_REG); > - > -out: > - return irq_handled; > + bus->irq_status ^= status_ack; > + return !bus->irq_status; > } > #endif /* CONFIG_I2C_SLAVE */ > > @@ -382,19 +377,19 @@ static int aspeed_i2c_is_irq_error(u32 irq_status) > > static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > { > - u32 irq_status, status_ack = 0, command = 0; > + u32 status_ack = 0, command = 0; > struct i2c_msg *msg; > u8 recv_byte; > int ret; > > - irq_status = readl(bus->base + ASPEED_I2C_INTR_STS_REG); > - /* Ack all interrupt bits. */ > - writel(irq_status, bus->base + ASPEED_I2C_INTR_STS_REG); > - > - if (irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) { > + if (bus->irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) { > bus->master_state = ASPEED_I2C_MASTER_INACTIVE; > status_ack |= ASPEED_I2CD_INTR_BUS_RECOVER_DONE; > goto out_complete; > + } else { > + /* Master is not currently active, irq was for someone else. */ > + if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE) > + goto out_no_complete; > } > > /* > @@ -402,20 +397,23 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > * should clear the command queue effectively taking us back to the > * INACTIVE state. > */ > - ret = aspeed_i2c_is_irq_error(irq_status); > - if (ret < 0) { > + ret = aspeed_i2c_is_irq_error(bus->irq_status); > + if (ret) { > dev_dbg(bus->dev, "received error interrupt: 0x%08x\n", > - irq_status); > + bus->irq_status); > bus->cmd_err = ret; > bus->master_state = ASPEED_I2C_MASTER_INACTIVE; > + status_ack |= (bus->irq_status & ASPEED_I2CD_INTR_ERRORS); > goto out_complete; > } > > /* We are in an invalid state; reset bus to a known state. */ > if (!bus->msgs) { > - dev_err(bus->dev, "bus in unknown state\n"); > + dev_err(bus->dev, "bus in unknown state irq_status: 0x%x\n", > + bus->irq_status); > bus->cmd_err = -EIO; > - if (bus->master_state != ASPEED_I2C_MASTER_STOP) > + if (bus->master_state != ASPEED_I2C_MASTER_STOP && > + bus->master_state != ASPEED_I2C_MASTER_INACTIVE) > aspeed_i2c_do_stop(bus); > goto out_no_complete; > } > @@ -427,8 +425,14 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > * then update the state and handle the new state below. > */ > if (bus->master_state == ASPEED_I2C_MASTER_START) { > - if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { > - pr_devel("no slave present at %02x\n", msg->addr); > + if (unlikely(!(bus->irq_status & ASPEED_I2CD_INTR_TX_ACK))) { > + if (unlikely(!(bus->irq_status & > + ASPEED_I2CD_INTR_TX_NAK))) { > + bus->cmd_err = -ENXIO; > + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; > + goto out_complete; > + } > + pr_devel("no slave present at %02x", msg->addr); Missing line feed character > status_ack |= ASPEED_I2CD_INTR_TX_NAK; > bus->cmd_err = -ENXIO; > aspeed_i2c_do_stop(bus); > @@ -447,11 +451,12 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > > switch (bus->master_state) { > case ASPEED_I2C_MASTER_TX: > - if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_NAK)) { > + if (unlikely(bus->irq_status & ASPEED_I2CD_INTR_TX_NAK)) { > dev_dbg(bus->dev, "slave NACKed TX\n"); > status_ack |= ASPEED_I2CD_INTR_TX_NAK; > goto error_and_stop; > - } else if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { > + } else if (unlikely(!(bus->irq_status & > + ASPEED_I2CD_INTR_TX_ACK))) { > dev_err(bus->dev, "slave failed to ACK TX\n"); > goto error_and_stop; > } > @@ -470,11 +475,11 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > goto out_no_complete; > case ASPEED_I2C_MASTER_RX_FIRST: > /* RX may not have completed yet (only address cycle) */ > - if (!(irq_status & ASPEED_I2CD_INTR_RX_DONE)) > + if (!(bus->irq_status & ASPEED_I2CD_INTR_RX_DONE)) > goto out_no_complete; > /* fallthrough intended */ > case ASPEED_I2C_MASTER_RX: > - if (unlikely(!(irq_status & ASPEED_I2CD_INTR_RX_DONE))) { > + if (unlikely(!(bus->irq_status & ASPEED_I2CD_INTR_RX_DONE))) { > dev_err(bus->dev, "master failed to RX\n"); > goto error_and_stop; > } > @@ -505,8 +510,11 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > } > goto out_no_complete; > case ASPEED_I2C_MASTER_STOP: > - if (unlikely(!(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP))) { > - dev_err(bus->dev, "master failed to STOP\n"); > + if (unlikely(!(bus->irq_status & > + ASPEED_I2CD_INTR_NORMAL_STOP))) { > + dev_err(bus->dev, > + "master failed to STOP irq_status:0x%x\n", > + bus->irq_status); > bus->cmd_err = -EIO; > /* Do not STOP as we have already tried. */ > } else { > @@ -518,7 +526,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > case ASPEED_I2C_MASTER_INACTIVE: > dev_err(bus->dev, > "master received interrupt 0x%08x, but is inactive\n", > - irq_status); > + bus->irq_status); > bus->cmd_err = -EIO; > /* Do not STOP as we should be inactive. */ > goto out_complete; > @@ -540,33 +548,40 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) > bus->master_xfer_result = bus->msgs_index + 1; > complete(&bus->cmd_complete); > out_no_complete: > - if (irq_status != status_ack) > - dev_err(bus->dev, > - "irq handled != irq. expected 0x%08x, but was 0x%08x\n", > - irq_status, status_ack); > - return !!irq_status; > + bus->irq_status ^= status_ack; > + return !bus->irq_status; > } > > static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) > { > struct aspeed_i2c_bus *bus = dev_id; > - bool ret; > + u32 irq_received; > > spin_lock(&bus->lock); > + irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); > + bus->irq_status = irq_received; > > #if IS_ENABLED(CONFIG_I2C_SLAVE) > - if (aspeed_i2c_slave_irq(bus)) { > - dev_dbg(bus->dev, "irq handled by slave.\n"); > - ret = true; > - goto out; > + if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) { > + if (!aspeed_i2c_master_irq(bus)) > + aspeed_i2c_slave_irq(bus); > + } else { > + if (!aspeed_i2c_slave_irq(bus)) > + aspeed_i2c_master_irq(bus); > } > +#else > + aspeed_i2c_master_irq(bus); > #endif /* CONFIG_I2C_SLAVE */ > > - ret = aspeed_i2c_master_irq(bus); > + if (bus->irq_status) > + dev_err(bus->dev, > + "irq handled != irq. expected 0x%08x, but was 0x%08x\n", > + irq_received, irq_received ^ bus->irq_status); > > -out: > + /* Ack all interrupt bits. */ > + writel(irq_received, bus->base + ASPEED_I2C_INTR_STS_REG); > spin_unlock(&bus->lock); > - return ret ? IRQ_HANDLED : IRQ_NONE; > + return bus->irq_status ? IRQ_NONE : IRQ_HANDLED; > } > > static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, >