diff mbox series

[v3] i2c: designware: call i2c_dw_read_clear_intrbits_slave() once

Message ID 20201023054027.13540-1-michael.wu@vatics.com
State Superseded
Headers show
Series [v3] i2c: designware: call i2c_dw_read_clear_intrbits_slave() once | expand

Commit Message

Michael Wu Oct. 23, 2020, 5:40 a.m. UTC
If some bits were cleared by i2c_dw_read_clear_intrbits_slave() in
i2c_dw_isr_slave() and not handled immediately, those cleared bits would
not be shown again by later i2c_dw_read_clear_intrbits_slave(). They
therefore were forgotten to be handled.

i2c_dw_read_clear_intrbits_slave() should be called once in an ISR and take
its returned state for all later handlings.

Signed-off-by: Michael Wu <michael.wu@vatics.com>
---

Change in v3:
 - revert deleted braces of 'else' branch in v2

Change in v2:
 - revert moving I2C_SLAVE_WRITE_REQUESTED reporting in v1

 drivers/i2c/busses/i2c-designware-slave.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

Comments

Jarkko Nikula Oct. 23, 2020, 6:27 a.m. UTC | #1
On 10/23/20 8:40 AM, Michael Wu wrote:
> If some bits were cleared by i2c_dw_read_clear_intrbits_slave() in
> i2c_dw_isr_slave() and not handled immediately, those cleared bits would
> not be shown again by later i2c_dw_read_clear_intrbits_slave(). They
> therefore were forgotten to be handled.
> 
> i2c_dw_read_clear_intrbits_slave() should be called once in an ISR and take
> its returned state for all later handlings.
> 
> Signed-off-by: Michael Wu <michael.wu@vatics.com>
> ---
> 
> Change in v3:
>   - revert deleted braces of 'else' branch in v2
> 
> Change in v2:
>   - revert moving I2C_SLAVE_WRITE_REQUESTED reporting in v1
> 
>   drivers/i2c/busses/i2c-designware-slave.c | 7 +------
>   1 file changed, 1 insertion(+), 6 deletions(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Michael Wu Oct. 28, 2020, 5:24 a.m. UTC | #2
Hi,

> On 10/23/20 8:40 AM, Michael Wu wrote:
> > If some bits were cleared by i2c_dw_read_clear_intrbits_slave() in
> > i2c_dw_isr_slave() and not handled immediately, those cleared bits would
> > not be shown again by later i2c_dw_read_clear_intrbits_slave(). They
> > therefore were forgotten to be handled.
> >
> > i2c_dw_read_clear_intrbits_slave() should be called once in an ISR and take
> > its returned state for all later handlings.
> > ---
> >   drivers/i2c/busses/i2c-designware-slave.c | 7 +------
> >   1 file changed, 1 insertion(+), 6 deletions(-)
> >
> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

There is another logic issue about the I2C_SLAVE_WRITE_REQUESTED reporting.
May I give patches based on this commit?

Michael Wu
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index 44974b53a626..13de01a0f75f 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -159,7 +159,6 @@  static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 	u32 raw_stat, stat, enabled, tmp;
 	u8 val = 0, slave_activity;
 
-	regmap_read(dev->map, DW_IC_INTR_STAT, &stat);
 	regmap_read(dev->map, DW_IC_ENABLE, &enabled);
 	regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_stat);
 	regmap_read(dev->map, DW_IC_STATUS, &tmp);
@@ -168,6 +167,7 @@  static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 	if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY) || !dev->slave)
 		return 0;
 
+	stat = i2c_dw_read_clear_intrbits_slave(dev);
 	dev_dbg(dev->dev,
 		"%#x STATUS SLAVE_ACTIVITY=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
 		enabled, slave_activity, raw_stat, stat);
@@ -188,11 +188,9 @@  static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 						 val);
 				}
 				regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
-				stat = i2c_dw_read_clear_intrbits_slave(dev);
 			} else {
 				regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
 				regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp);
-				stat = i2c_dw_read_clear_intrbits_slave(dev);
 			}
 			if (!i2c_slave_event(dev->slave,
 					     I2C_SLAVE_READ_REQUESTED,
@@ -207,7 +205,6 @@  static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 			regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp);
 
 		i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
-		stat = i2c_dw_read_clear_intrbits_slave(dev);
 		return 1;
 	}
 
@@ -219,7 +216,6 @@  static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 			dev_vdbg(dev->dev, "Byte %X acked!", val);
 	} else {
 		i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
-		stat = i2c_dw_read_clear_intrbits_slave(dev);
 	}
 
 	return 1;
@@ -230,7 +226,6 @@  static irqreturn_t i2c_dw_isr_slave(int this_irq, void *dev_id)
 	struct dw_i2c_dev *dev = dev_id;
 	int ret;
 
-	i2c_dw_read_clear_intrbits_slave(dev);
 	ret = i2c_dw_irq_handler_slave(dev);
 	if (ret > 0)
 		complete(&dev->cmd_complete);