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 more in multi-master environment 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. Changes since v1: - Fixed a grammer issue in commit message. - Added a missing line feed character into a message printing. Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx> --- drivers/i2c/busses/i2c-aspeed.c | 135 ++++++++++++++++++-------------- 1 file changed, 75 insertions(+), 60 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index efb89422d496..75431e305073 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; } @@ -427,7 +425,13 @@ 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))) { + 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\n", msg->addr); status_ack |= ASPEED_I2CD_INTR_TX_NAK; bus->cmd_err = -ENXIO; @@ -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, -- 2.18.0