[Skiboot] [RFC PATCH 4/6] core/flash: Make opal_flash_op() actually asynchronous

[Vasant Hegde]

On 02/28/2019 11:48 AM, Stewart Smith wrote:
> From: Cyril Bur <cyril.bur at au1.ibm.com>
> 

.../...


> -err:
> +	if (size - len) {
> +		/* Work remains */
> +		schedule_timer(&flash->async.poller, 0);

Why are we calling schedule_time with 0?


>   }
> diff --git a/core/timer.c b/core/timer.c
> index 1c539517839e..c68f978ccb07 100644
> --- a/core/timer.c
> +++ b/core/timer.c
> @@ -199,6 +199,7 @@ static void __check_poll_timers(uint64_t now)
>   static void __check_timers(uint64_t now)
>   {
>   	struct timer *t;
> +	uint64_t stop = now + msecs_to_tb(50); /* Run timers for max 5ms */

I'm not sure why we need this change. Can you please elaborate?


> 
>   	for (;;) {
>   		t = list_top(&timer_list, struct timer, link);
> @@ -229,6 +230,12 @@ static void __check_timers(uint64_t now)
> 
>   		/* Update time stamp */
>   		now = mftb();
> +
> +		/* Only run timers for a limited time to avoid jitter */
> +		if (now > stop) {
> +			prlog(PR_PRINTF, "Run timers for > 50ms\n");
> +			break;
> +		}
>   	}
>   }

-Vasant