From mboxrd@z Thu Jan 1 00:00:00 1970 From: jae.hyun.yoo@linux.intel.com (Jae Hyun Yoo) Date: Mon, 23 Jul 2018 11:13:30 -0700 Subject: [PATCH i2c-next] i2c: aspeed: Handle master/slave combined irq events properly In-Reply-To: <58d31319-83c0-969b-e3fd-4273818929fc@linux.intel.com> References: <20180723174808.4007-1-jae.hyun.yoo@linux.intel.com> <58d31319-83c0-969b-e3fd-4273818929fc@linux.intel.com> Message-ID: <6721ef3b-2c74-9f4a-1b67-5335e7878a0c@linux.intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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, >>