diff mbox series

[4/4] i2c: xiic: Fix Tx Interrupt path for grouped messages

Message ID 20220420075924.14546-5-shubhrajyoti.datta@xilinx.com
State New
Headers show
Series i2c: xiic: misc fixes | expand

Commit Message

Shubhrajyoti Datta April 20, 2022, 7:59 a.m. UTC 
From: Raviteja Narayanam <raviteja.narayanam@xilinx.com>

When a group of messages are sent from user space as a set, if
the last message has less than Tx FIFO DEPTH number of bytes
to transfer, Tx half empty interrupt is triggered continuously
from the hardware. It is due to Bus not busy interrupt coming
along with Tx half empty and tx empty.

Hence, service the Tx interrupts before Bus not busy interrupt
to update the i2c message status correctly.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/i2c/busses/i2c-xiic.c | 38 ++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 18 deletions(-)

Comments

Wolfram Sang May 14, 2022, 2:04 p.m. UTC | #1 
On Wed, Apr 20, 2022 at 01:29:24PM +0530, Shubhrajyoti Datta wrote:
> From: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
> 
> When a group of messages are sent from user space as a set, if
> the last message has less than Tx FIFO DEPTH number of bytes
> to transfer, Tx half empty interrupt is triggered continuously
> from the hardware. It is due to Bus not busy interrupt coming
> along with Tx half empty and tx empty.
> 
> Hence, service the Tx interrupts before Bus not busy interrupt
> to update the i2c message status correctly.
> 
> Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

Applied to for-next, thanks!
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index eb4d34e7c0fe..953f7cffe0d8 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -468,24 +468,6 @@  static irqreturn_t xiic_process(int irq, void *dev_id)
 			}
 		}
 	}
-	if (pend & XIIC_INTR_BNB_MASK) {
-		/* IIC bus has transitioned to not busy */
-		clr |= XIIC_INTR_BNB_MASK;
-
-		/* The bus is not busy, disable BusNotBusy interrupt */
-		xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK);
-
-		if (!i2c->tx_msg)
-			goto out;
-
-		wakeup_req = 1;
-
-		if (i2c->nmsgs == 1 && !i2c->rx_msg &&
-		    xiic_tx_space(i2c) == 0)
-			wakeup_code = STATE_DONE;
-		else
-			wakeup_code = STATE_ERROR;
-	}
 	if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {
 		/* Transmit register/FIFO is empty or ½ empty */
 
@@ -522,6 +504,26 @@  static irqreturn_t xiic_process(int irq, void *dev_id)
 			 */
 			xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
 	}
+
+	if (pend & XIIC_INTR_BNB_MASK) {
+		/* IIC bus has transitioned to not busy */
+		clr |= XIIC_INTR_BNB_MASK;
+
+		/* The bus is not busy, disable BusNotBusy interrupt */
+		xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK);
+
+		if (!i2c->tx_msg)
+			goto out;
+
+		wakeup_req = 1;
+
+		if (i2c->nmsgs == 1 && !i2c->rx_msg &&
+		    xiic_tx_space(i2c) == 0)
+			wakeup_code = STATE_DONE;
+		else
+			wakeup_code = STATE_ERROR;
+	}
+
 out:
 	dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);