From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jae Hyun Yoo Subject: Re: [PATCH i2c-next] i2c: aspeed: Handle master/slave combined irq events properly Date: Mon, 23 Jul 2018 11:13:30 -0700 Message-ID: <6721ef3b-2c74-9f4a-1b67-5335e7878a0c@linux.intel.com> References: <20180723174808.4007-1-jae.hyun.yoo@linux.intel.com> <58d31319-83c0-969b-e3fd-4273818929fc@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <58d31319-83c0-969b-e3fd-4273818929fc@linux.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: James Feist , 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 List-Id: linux-i2c@vger.kernel.org Thanks James for the review. Please see my inline answers. On 7/23/2018 11:10 AM, James Feist wrote: > 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 > Thanks! Will fix it. >> 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 Thanks for your pointing it out. Will add '\n' at the end of the message. >>               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, >>