[PATCH v2 01/10] i2c: xiic: Fix Tx Interrupt path for grouped messages
From: Raviteja Narayanam <hidden>
Date: 2021-06-26 10:28:44
Also in:
linux-i2c, lkml
Subsystem:
arm/zynq architecture, i2c subsystem, i2c subsystem host drivers, the rest · Maintainers:
Michal Simek, Wolfram Sang, Andi Shyti, Linus Torvalds
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 <redacted> --- drivers/i2c/busses/i2c-xiic.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-)
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index 2a8568b97c14..b0cfd9d15467 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c@@ -453,22 +453,6 @@ 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; - - if ((i2c->nmsgs == 1) && !i2c->rx_msg && - xiic_tx_space(i2c) == 0) - xiic_wakeup(i2c, STATE_DONE); - else - xiic_wakeup(i2c, STATE_ERROR); - } if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) { /* Transmit register/FIFO is empty or ½ empty */
@@ -505,6 +489,24 @@ 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; + + if (i2c->nmsgs == 1 && !i2c->rx_msg && + xiic_tx_space(i2c) == 0) + xiic_wakeup(i2c, STATE_DONE); + else + xiic_wakeup(i2c, STATE_ERROR); + } + out: dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
--
2.25.1
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