Messages in this thread | | | Subject | Re: [PATCH i2c-next v6] i2c: aspeed: Handle master/slave combined irq events properly | From | Jae Hyun Yoo <> | Date | Thu, 6 Sep 2018 10:32:36 -0700 |
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On 9/6/2018 10:26 AM, Brendan Higgins wrote: > On Thu, Aug 23, 2018 at 3:58 PM Jae Hyun Yoo > <jae.hyun.yoo@linux.intel.com> 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 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. >> >> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >> --- >> Changes since v5: >> - Changed variable names in irq hanlders to represent proper meaning. >> - Fixed an error printing message again to make it use the irq_handled variable. >> >> Changes since v4: >> - Fixed an error printing message that handlers didn't handle all interrupts. >> >> Changes since v3: >> - Fixed typos in a comment. >> >> Changes since v2: >> - Changed the name of ASPEED_I2CD_INTR_ERRORS to ASPEED_I2CD_INTR_MASTER_ERRORS >> - Removed a member irq_status from the struct aspeed_i2c_bus and changed >> master_irq and slave_irq handlers to make them return status_ack. >> - Added a comment to explain why it needs to try both irq handlers. >> >> Changes since v1: >> - Fixed a grammar issue in commit message. >> - Added a missing line feed character into a message printing. >> >> drivers/i2c/busses/i2c-aspeed.c | 131 ++++++++++++++++++-------------- >> 1 file changed, 76 insertions(+), 55 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c >> index a4f956c6d567..c258c4d9a4c0 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_MASTER_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 | \ >> @@ -227,32 +232,26 @@ 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) >> +static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> { >> - u32 command, irq_status, status_ack = 0; >> + u32 command, irq_handled = 0; >> struct i2c_client *slave = bus->slave; >> - bool irq_handled = true; >> u8 value; >> >> - if (!slave) { >> - irq_handled = false; >> - goto out; >> - } >> + if (!slave) >> + return 0; >> >> 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) { >> - status_ack |= ASPEED_I2CD_INTR_SLAVE_MATCH; >> + irq_handled |= 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 irq_handled; >> >> dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", >> irq_status, command); >> @@ -269,31 +268,31 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) >> bus->slave_state = >> ASPEED_I2C_SLAVE_WRITE_REQUESTED; >> } >> - status_ack |= ASPEED_I2CD_INTR_RX_DONE; >> + irq_handled |= ASPEED_I2CD_INTR_RX_DONE; >> } >> >> /* Slave was asked to stop. */ >> if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { >> - status_ack |= ASPEED_I2CD_INTR_NORMAL_STOP; >> + irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; >> bus->slave_state = ASPEED_I2C_SLAVE_STOP; >> } >> if (irq_status & ASPEED_I2CD_INTR_TX_NAK) { >> - status_ack |= ASPEED_I2CD_INTR_TX_NAK; >> + irq_handled |= ASPEED_I2CD_INTR_TX_NAK; >> bus->slave_state = ASPEED_I2C_SLAVE_STOP; >> } >> + if (irq_status & ASPEED_I2CD_INTR_TX_ACK) >> + irq_handled |= ASPEED_I2CD_INTR_TX_ACK; >> >> switch (bus->slave_state) { >> case ASPEED_I2C_SLAVE_READ_REQUESTED: >> if (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)) >> dev_err(bus->dev, >> "Expected ACK after processed read.\n"); >> @@ -317,13 +316,6 @@ 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; >> } >> #endif /* CONFIG_I2C_SLAVE */ >> @@ -380,21 +372,21 @@ static int aspeed_i2c_is_irq_error(u32 irq_status) >> return 0; >> } >> >> -static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) >> +static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> { >> - u32 irq_status, status_ack = 0, command = 0; >> + u32 irq_handled = 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) { >> bus->master_state = ASPEED_I2C_MASTER_INACTIVE; >> - status_ack |= ASPEED_I2CD_INTR_BUS_RECOVER_DONE; >> + irq_handled |= 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; >> } >> >> /* >> @@ -403,19 +395,22 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) >> * INACTIVE state. >> */ >> ret = aspeed_i2c_is_irq_error(irq_status); >> - if (ret < 0) { >> + if (ret) { >> dev_dbg(bus->dev, "received error interrupt: 0x%08x\n", >> irq_status); >> bus->cmd_err = ret; >> bus->master_state = ASPEED_I2C_MASTER_INACTIVE; >> + irq_handled |= (irq_status & ASPEED_I2CD_INTR_MASTER_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", >> + 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; >> } >> @@ -428,13 +423,18 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) >> */ >> if (bus->master_state == ASPEED_I2C_MASTER_START) { >> if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { >> + if (unlikely(!(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; >> + irq_handled |= ASPEED_I2CD_INTR_TX_NAK; >> bus->cmd_err = -ENXIO; >> aspeed_i2c_do_stop(bus); >> goto out_no_complete; >> } >> - status_ack |= ASPEED_I2CD_INTR_TX_ACK; >> + irq_handled |= ASPEED_I2CD_INTR_TX_ACK; >> if (msg->len == 0) { /* SMBUS_QUICK */ >> aspeed_i2c_do_stop(bus); >> goto out_no_complete; >> @@ -449,13 +449,13 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) >> case ASPEED_I2C_MASTER_TX: >> if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_NAK)) { >> dev_dbg(bus->dev, "slave NACKed TX\n"); >> - status_ack |= ASPEED_I2CD_INTR_TX_NAK; >> + irq_handled |= ASPEED_I2CD_INTR_TX_NAK; >> goto error_and_stop; >> } else if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { >> dev_err(bus->dev, "slave failed to ACK TX\n"); >> goto error_and_stop; >> } >> - status_ack |= ASPEED_I2CD_INTR_TX_ACK; >> + irq_handled |= ASPEED_I2CD_INTR_TX_ACK; >> /* fallthrough intended */ >> case ASPEED_I2C_MASTER_TX_FIRST: >> if (bus->buf_index < msg->len) { >> @@ -478,7 +478,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus) >> dev_err(bus->dev, "master failed to RX\n"); >> goto error_and_stop; >> } >> - status_ack |= ASPEED_I2CD_INTR_RX_DONE; >> + irq_handled |= ASPEED_I2CD_INTR_RX_DONE; >> >> recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; >> msg->buf[bus->buf_index++] = recv_byte; >> @@ -506,11 +506,13 @@ 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"); >> + dev_err(bus->dev, >> + "master failed to STOP. irq_status:0x%x\n", >> + irq_status); >> bus->cmd_err = -EIO; >> /* Do not STOP as we have already tried. */ >> } else { >> - status_ack |= ASPEED_I2CD_INTR_NORMAL_STOP; >> + irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; >> } >> >> bus->master_state = ASPEED_I2C_MASTER_INACTIVE; >> @@ -540,33 +542,52 @@ 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; >> + return irq_handled; >> } >> >> static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) >> { >> struct aspeed_i2c_bus *bus = dev_id; >> - bool ret; >> + u32 irq_received, irq_remaining, irq_handled; >> >> spin_lock(&bus->lock); >> + irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); >> + irq_remaining = 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; >> + /* >> + * In most cases, interrupt bits will be set one by one, although >> + * multiple interrupt bits could be set at the same time. It's also >> + * possible that master interrupt bits could be set along with slave >> + * interrupt bits. Each case needs to be handled using corresponding >> + * handlers depending on the current state. >> + */ >> + if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) { >> + irq_handled = aspeed_i2c_master_irq(bus, irq_remaining); >> + irq_remaining &= ~irq_handled; >> + if (irq_remaining) >> + irq_handled |= aspeed_i2c_slave_irq(bus, irq_remaining); >> + } else { >> + irq_handled = aspeed_i2c_slave_irq(bus, irq_remaining); >> + irq_remaining &= ~irq_handled; >> + if (irq_remaining) >> + irq_handled |= aspeed_i2c_master_irq(bus, >> + irq_remaining); >> } >> +#else >> + irq_handled = aspeed_i2c_master_irq(bus, irq_remaining); >> #endif /* CONFIG_I2C_SLAVE */ >> >> - ret = aspeed_i2c_master_irq(bus); >> + irq_remaining &= ~irq_handled; >> + if (irq_remaining) >> + dev_err(bus->dev, >> + "irq handled != irq. expected 0x%08x, but was 0x%08x\n", >> + irq_received, irq_handled); >> >> -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 irq_remaining ? IRQ_NONE : IRQ_HANDLED; >> } >> >> static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, >> -- >> 2.18.0 >> > > Looks awesome! Thanks! > > Reviewed-by: Brendan Higgins <brendanhiggins@google.com> >
Thanks a lot for your review Brendan!
-Jae
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