Re: [PATCH 5/7] i2c: img-scb: remove fifo EMPTYING interrupts handle

[James Hogan <james.hogan-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>]

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On 27/07/15 12:56, Sifan Naeem wrote:
> This interrupt could have been useful for repeated start transfers
> as the current transfer could be marked as complete while it's
> processing the final byte of the transfer.
> But having to use the transaction halt interrupt to safely control
> repeated start transfers, means handling of the fifo EMPTYING
> interrupts is no longer necessary.
> 
> Handling this interrupt along with Transaction Halt interrupt can
> cause erratic behaviour.

I'd be interested to know the cause of the erratic behaviour. It feels a
little like we're just masking a real bug somewhere.

Cheers
James

> 
> Signed-off-by: Sifan Naeem <sifan.naeem-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-img-scb.c |    6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-img-scb.c b/drivers/i2c/busses/i2c-img-scb.c
> index efad4d7..10141a9 100644
> --- a/drivers/i2c/busses/i2c-img-scb.c
> +++ b/drivers/i2c/busses/i2c-img-scb.c
> @@ -154,7 +154,6 @@
>  #define INT_TIMING			BIT(18)
>  
>  #define INT_FIFO_FULL_FILLING	(INT_FIFO_FULL  | INT_FIFO_FILLING)
> -#define INT_FIFO_EMPTY_EMPTYING	(INT_FIFO_EMPTY | INT_FIFO_EMPTYING)
>  
>  /* Level interrupts need clearing after handling instead of before */
>  #define INT_LEVEL			0x01e00
> @@ -176,8 +175,7 @@
>  					 INT_WRITE_ACK_ERR    | \
>  					 INT_FIFO_FULL        | \
>  					 INT_FIFO_FILLING     | \
> -					 INT_FIFO_EMPTY       | \
> -					 INT_FIFO_EMPTYING)
> +					 INT_FIFO_EMPTY)
>  
>  #define INT_ENABLE_MASK_WAITSTOP	(INT_SLAVE_EVENT      | \
>  					 INT_ADDR_ACK_ERR     | \
> @@ -910,7 +908,7 @@ static unsigned int img_i2c_auto(struct img_i2c *i2c,
>  			}
>  		}
>  	} else {
> -		if (int_status & INT_FIFO_EMPTY_EMPTYING) {
> +		if (int_status & INT_FIFO_EMPTY) {
>  			if (i2c->msg.len == 0) {
>  				if (i2c->last_msg)
>  					return ISR_WAITSTOP;
> 


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