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 <[email protected]>
---
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);
-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
On Mon, Aug 20, 2018 at 1:16 PM Jae Hyun Yoo
<[email protected]> 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 <[email protected]>
> ---
> 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
<[email protected]>"
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
> <[email protected]> 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 <[email protected]>
>> ---
>> 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
> <[email protected]>"
>
> Cheers
>
Thanks a lot for your review. I really appreciate it. Will submit the v5
patch soon.
Jae