[PATCH] i2c: cadence: Fix the driver in interrupt flurry case

[PATCH] i2c: cadence: Fix the driver in interrupt flurry case

[shubhrajyoti.datta]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

In case there are a lot of interrupts then the hold bit is not
released protect the code by making it atomic by disabling interrupts.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 drivers/i2c/busses/i2c-cadence.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b136057..92829be 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -365,6 +365,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 {
 	unsigned int ctrl_reg;
 	unsigned int isr_status;
+	unsigned long flags;
 
 	id->p_recv_buf = id->p_msg->buf;
 	id->recv_count = id->p_msg->len;
@@ -405,6 +406,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 		cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET);
 	}
 
+	local_irq_save(flags);
 	/* Set the slave address in address register - triggers operation */
 	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
 						CDNS_I2C_ADDR_OFFSET);
@@ -413,6 +415,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 		((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) &&
 		(id->recv_count <= CDNS_I2C_FIFO_DEPTH))
 			cdns_i2c_clear_bus_hold(id);
+	local_irq_restore(flags);
 	cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
 }
 
-- 
2.1.1

Re: [PATCH] i2c: cadence: Fix the driver in interrupt flurry case

[Michal Simek]

On 15. 02. 19 13:03, shubhrajyoti.datta@gmail.com wrote:
> From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> 
> In case there are a lot of interrupts then the hold bit is not
> released protect the code by making it atomic by disabling interrupts.

There are two sentences in one.

Isn't it "released. Protect"?

> 
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> ---
>  drivers/i2c/busses/i2c-cadence.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
> index b136057..92829be 100644
> --- a/drivers/i2c/busses/i2c-cadence.c
> +++ b/drivers/i2c/busses/i2c-cadence.c
> @@ -365,6 +365,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
>  {
>  	unsigned int ctrl_reg;
>  	unsigned int isr_status;
> +	unsigned long flags;
>  
>  	id->p_recv_buf = id->p_msg->buf;
>  	id->recv_count = id->p_msg->len;
> @@ -405,6 +406,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
>  		cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET);
>  	}
>  
> +	local_irq_save(flags);
>  	/* Set the slave address in address register - triggers operation */
>  	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
>  						CDNS_I2C_ADDR_OFFSET);
> @@ -413,6 +415,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
>  		((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) &&
>  		(id->recv_count <= CDNS_I2C_FIFO_DEPTH))
>  			cdns_i2c_clear_bus_hold(id);
> +	local_irq_restore(flags);
>  	cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
>  }
>  
> 

The rest looks good.
M