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Subject[PATCH] i2c: cadence: Implement timeout
Date
From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

In some cases we are waiting in a loop. Replace the infinite wait with
the timeout.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
drivers/i2c/busses/i2c-cadence.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b136057..9c38278 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -209,6 +209,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
struct cdns_i2c *id = ptr;
/* Signal completion only after everything is updated */
int done_flag = 0;
+ unsigned int timeout;
irqreturn_t status = IRQ_NONE;

isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
@@ -235,6 +236,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
((isr_status & CDNS_I2C_IXR_COMP) ||
(isr_status & CDNS_I2C_IXR_DATA))) {
/* Read data if receive data valid is set */
+ timeout = 1000;
while (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) &
CDNS_I2C_SR_RXDV) {
/*
@@ -253,6 +255,16 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)

if (cdns_is_holdquirk(id, hold_quirk))
break;
+ timeout--;
+ if (timeout)
+ mdelay(1);
+ else
+ break;
+ }
+ if (!timeout) {
+ id->err_status = -ETIMEDOUT;
+ complete(&id->xfer_done);
+ return IRQ_HANDLED;
}

/*
@@ -262,12 +274,22 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
* maintain transfer size non-zero while performing a large
* receive operation.
*/
+ timeout = 1000;
if (cdns_is_holdquirk(id, hold_quirk)) {
/* wait while fifo is full */
- while (cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) !=
- (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH))
- ;
-
+ while ((cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) !=
+ (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH))) {
+ timeout--;
+ if (timeout)
+ mdelay(1);
+ else
+ break;
+ }
+ if (!timeout) {
+ id->err_status = -ETIMEDOUT;
+ complete(&id->xfer_done);
+ return IRQ_HANDLED;
+ }
/*
* Check number of bytes to be received against maximum
* transfer size and update register accordingly.
--
2.1.1
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