| Message ID | 20180820201632.29229-1-jae.hyun.yoo@linux.intel.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [i2c-next,v4] i2c: aspeed: Handle master/slave combined irq events properly | expand |
On Mon, Aug 20, 2018 at 1:16 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 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 | 110 +++++++++++++++++++------------- > 1 file changed, 65 insertions(+), 45 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c > index a4f956c6d567..09eb4a9b355c 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 | \ > @@ -227,20 +232,16 @@ 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, 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 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) { > @@ -249,10 +250,8 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) > } > > /* 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 status_ack; > > dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", > irq_status, command); > @@ -281,19 +280,19 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) > status_ack |= ASPEED_I2CD_INTR_TX_NAK; > bus->slave_state = ASPEED_I2C_SLAVE_STOP; > } > + if (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) > 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"); > @@ -317,14 +316,7 @@ 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; > + return status_ack; > } > #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 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) { > 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; > } > > /* > @@ -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; > + status_ack |= (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; > } > @@ -428,6 +423,11 @@ 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; > bus->cmd_err = -ENXIO; > @@ -506,7 +506,9 @@ 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 { > @@ -540,33 +542,51 @@ 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 status_ack; > } > > 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_status, irq_acked; > > spin_lock(&bus->lock); > + irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); > + 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; > + /* > + * 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_acked = aspeed_i2c_master_irq(bus, irq_status); > + irq_status &= ~irq_acked; > + if (irq_status) > + irq_acked = aspeed_i2c_slave_irq(bus, irq_status); > + } else { > + irq_acked = aspeed_i2c_slave_irq(bus, irq_status); > + irq_status &= ~irq_acked; > + if (irq_status) > + irq_acked = aspeed_i2c_master_irq(bus, irq_status); > } > +#else > + irq_acked = aspeed_i2c_master_irq(bus, irq_status); > #endif /* CONFIG_I2C_SLAVE */ > > - ret = aspeed_i2c_master_irq(bus); > + irq_status &= ~irq_acked; > + if (irq_status) > + dev_err(bus->dev, > + "irq handled != irq. expected 0x%08x, but was 0x%08x\n", > + irq_received, irq_received ^ irq_status); I think you want to use `irq_acked` here. > > -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_status ? IRQ_NONE : IRQ_HANDLED; > } > > static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, > -- > 2.18.0 > One minor issue and then I think we are good to go! Also, sorry about not reviewing your last patch. I missed it apparently. Feel free to mark the next patch "Reviewed-by: Brendan Higgins <brendanhiggins@google.com>" Cheers
Hi Brendan, On 8/22/2018 11:46 PM, Brendan Higgins wrote: > On Mon, Aug 20, 2018 at 1:16 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 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 | 110 +++++++++++++++++++------------- >> 1 file changed, 65 insertions(+), 45 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c >> index a4f956c6d567..09eb4a9b355c 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 | \ >> @@ -227,20 +232,16 @@ 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, 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 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) { >> @@ -249,10 +250,8 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) >> } >> >> /* 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 status_ack; >> >> dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", >> irq_status, command); >> @@ -281,19 +280,19 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) >> status_ack |= ASPEED_I2CD_INTR_TX_NAK; >> bus->slave_state = ASPEED_I2C_SLAVE_STOP; >> } >> + if (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) >> 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"); >> @@ -317,14 +316,7 @@ 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; >> + return status_ack; >> } >> #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 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) { >> 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; >> } >> >> /* >> @@ -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; >> + status_ack |= (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; >> } >> @@ -428,6 +423,11 @@ 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; >> bus->cmd_err = -ENXIO; >> @@ -506,7 +506,9 @@ 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 { >> @@ -540,33 +542,51 @@ 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 status_ack; >> } >> >> 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_status, irq_acked; >> >> spin_lock(&bus->lock); >> + irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); >> + 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; >> + /* >> + * 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_acked = aspeed_i2c_master_irq(bus, irq_status); >> + irq_status &= ~irq_acked; >> + if (irq_status) >> + irq_acked = aspeed_i2c_slave_irq(bus, irq_status); >> + } else { >> + irq_acked = aspeed_i2c_slave_irq(bus, irq_status); >> + irq_status &= ~irq_acked; >> + if (irq_status) >> + irq_acked = aspeed_i2c_master_irq(bus, irq_status); >> } >> +#else >> + irq_acked = aspeed_i2c_master_irq(bus, irq_status); >> #endif /* CONFIG_I2C_SLAVE */ >> >> - ret = aspeed_i2c_master_irq(bus); >> + irq_status &= ~irq_acked; >> + if (irq_status) >> + dev_err(bus->dev, >> + "irq handled != irq. expected 0x%08x, but was 0x%08x\n", >> + irq_received, irq_received ^ irq_status); > > I think you want to use `irq_acked` here. > Yes, right. I'll fix the message printing. Thanks for your pointing it out. >> >> -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_status ? IRQ_NONE : IRQ_HANDLED; >> } >> >> static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, >> -- >> 2.18.0 >> > > One minor issue and then I think we are good to go! > > Also, sorry about not reviewing your last patch. I missed it apparently. > > Feel free to mark the next patch "Reviewed-by: Brendan Higgins > <brendanhiggins@google.com>" > > Cheers > Thanks a lot for your review. I really appreciate it. Will submit the v5 patch soon. Jae
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index a4f956c6d567..09eb4a9b355c 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 | \ @@ -227,20 +232,16 @@ 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, 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 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) { @@ -249,10 +250,8 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) } /* 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 status_ack; dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", irq_status, command); @@ -281,19 +280,19 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus) status_ack |= ASPEED_I2CD_INTR_TX_NAK; bus->slave_state = ASPEED_I2C_SLAVE_STOP; } + if (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) 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"); @@ -317,14 +316,7 @@ 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; + return status_ack; } #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 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) { 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; } /* @@ -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; + status_ack |= (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; } @@ -428,6 +423,11 @@ 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; bus->cmd_err = -ENXIO; @@ -506,7 +506,9 @@ 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 { @@ -540,33 +542,51 @@ 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 status_ack; } 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_status, irq_acked; spin_lock(&bus->lock); + irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); + 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; + /* + * 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_acked = aspeed_i2c_master_irq(bus, irq_status); + irq_status &= ~irq_acked; + if (irq_status) + irq_acked = aspeed_i2c_slave_irq(bus, irq_status); + } else { + irq_acked = aspeed_i2c_slave_irq(bus, irq_status); + irq_status &= ~irq_acked; + if (irq_status) + irq_acked = aspeed_i2c_master_irq(bus, irq_status); } +#else + irq_acked = aspeed_i2c_master_irq(bus, irq_status); #endif /* CONFIG_I2C_SLAVE */ - ret = aspeed_i2c_master_irq(bus); + irq_status &= ~irq_acked; + if (irq_status) + dev_err(bus->dev, + "irq handled != irq. expected 0x%08x, but was 0x%08x\n", + irq_received, irq_received ^ 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 irq_status ? IRQ_NONE : IRQ_HANDLED; } static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
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 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 | 110 +++++++++++++++++++------------- 1 file changed, 65 insertions(+), 45 deletions(-)