[U-Boot] [PATCH 1/1 v3] console: USB: KBD: Fix incorrect autoboot timeout

[Jim Lin]

Thanks for pointing out the potential issue.

-----Original Message-----
From: Jon Hunter [mailto:jon-hunter at ti.com] 
Sent: Thursday, March 21, 2013 7:57 AM
To: Jim Lin
Cc: u-boot at lists.denx.de; marex at denx.de; wd at denx.de; trini at ti.com; Tom Warren
Subject: Re: [U-Boot] [PATCH 1/1 v3] console: USB: KBD: Fix incorrect autoboot timeout


On 01/24/2013 05:05 AM, Jim Lin wrote:
> Autoboot timeout defined by CONFIG_BOOTDELAY will not be accurate if 
> CONFIG_USB_KEYBOARD and CONFIG_SYS_USB_EVENT_POLL are defined in 
> configuration file and when tstc() function for checking key pressed 
> takes longer time than 10 ms (e.g., 50 ms) to finish.
> 
> Signed-off-by: Jim Lin <jilin at nvidia.com>
> ---
> Changes in v2:
>    - use do-while and get_timer to count timeout.
> Changes in v3:
>    - revert original udelay(10000); for safety.
> 
>  common/main.c |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/common/main.c b/common/main.c index b145f85..dcd2a42 
> 100644
> --- a/common/main.c
> +++ b/common/main.c
> @@ -225,6 +225,7 @@ static inline
>  int abortboot(int bootdelay)
>  {
>  	int abort = 0;
> +	unsigned long ts;
>  
>  #ifdef CONFIG_MENUPROMPT
>  	printf(CONFIG_MENUPROMPT);
> @@ -248,11 +249,10 @@ int abortboot(int bootdelay)  #endif
>  
>  	while ((bootdelay > 0) && (!abort)) {
> -		int i;
> -
>  		--bootdelay;
> -		/* delay 100 * 10ms */
> -		for (i=0; !abort && i<100; ++i) {
> +		/* delay 1000 ms */
> +		ts = get_timer(0);
> +		do {
>  			if (tstc()) {	/* we got a key press	*/
>  				abort  = 1;	/* don't auto boot	*/
>  				bootdelay = 0;	/* no more delay	*/
> @@ -264,7 +264,7 @@ int abortboot(int bootdelay)
>  				break;
>  			}
>  			udelay(10000);
> -		}
> +		} while (!abort && get_timer(ts) < 1000);
>  
>  		printf("\b\b\b%2d ", bootdelay);
>  	}

This change is causing problems with auto-delay on one of my boards by making it inaccurate :-(

The question is what should get_timer() be returning? If it is meant to be milliseconds then I guess I need to fix get_timer() for my board.
However, if it is just meant to be timer ticks at the SYS_HZ rate then I don't see how the above change guarantees the do-while loop waits 1000 ms per iteration without normalising to SYS_HZ.

For my board I made the following change to make it work ...

diff --git a/common/main.c b/common/main.c index a15f020..32c4f8a 100644
--- a/common/main.c
+++ b/common/main.c
@@ -264,7 +264,7 @@ int abortboot(int bootdelay)
                                break;
                        }
                        udelay(10000);
-               } while (!abort && get_timer(ts) < 1000);
+               } while (!abort && !(get_timer(ts) / CONFIG_SYS_HZ));

                printf("\b\b\b%2d ", bootdelay);

--
nvpublic