[PATCH u-boot-marvell 13/13] tools: kwboot: Resend first 3 xmodem retry packets immediately

[Stefan Roese]

On 25.10.21 15:13, Marek Behún wrote:
> From: Pali Rohár <pali at kernel.org>
> 
> Currently when kwboot receive some garbage reply which does not understand,
> it waits 1s before it tries to resend packet again.
> 
> The most common error on UART is that receiver sees some bit flipped which
> results in invalid reply.
> 
> This behavior slows down xmodem transfer over UART as basically on every
> error kwboot is waiting one second.
> 
> To fix this, try to resend xmodem packet for first 3 attempts immediately
> without any delay. If broken reply is received also after the 3 attempts,
> continue retrying with 1s delay like it was before.
> 
> Signed-off-by: Pali Rohár <pali at kernel.org>
> Reviewed-by: Marek Behún <marek.behun at nic.cz>

Reviewed-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan

> ---
>   tools/kwboot.c | 13 ++++++++++---
>   1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/kwboot.c b/tools/kwboot.c
> index 16c5a84825..bb7cae9f05 100644
> --- a/tools/kwboot.c
> +++ b/tools/kwboot.c
> @@ -851,7 +851,8 @@ kwboot_baud_magic_handle(int fd, char c, int baudrate)
>   }
>   
>   static int
> -kwboot_xm_recv_reply(int fd, char *c, int allow_non_xm, int *non_xm_print,
> +kwboot_xm_recv_reply(int fd, char *c, int nak_on_non_xm,
> +		     int allow_non_xm, int *non_xm_print,
>   		     int baudrate, int *baud_changed)
>   {
>   	int timeout = allow_non_xm ? KWBOOT_HDR_RSP_TIMEO : blk_rsp_timeo;
> @@ -904,6 +905,10 @@ kwboot_xm_recv_reply(int fd, char *c, int allow_non_xm, int *non_xm_print,
>   				*non_xm_print = 1;
>   			}
>   		} else {
> +			if (nak_on_non_xm) {
> +				*c = NAK;
> +				break;
> +			}
>   			timeout = recv_until - _now();
>   			if (timeout < 0) {
>   				errno = ETIMEDOUT;
> @@ -937,7 +942,8 @@ kwboot_xm_sendblock(int fd, struct kwboot_block *block, int allow_non_xm,
>   			*done_print = 1;
>   		}
>   
> -		rc = kwboot_xm_recv_reply(fd, &c, allow_non_xm, &non_xm_print,
> +		rc = kwboot_xm_recv_reply(fd, &c, retries < 3,
> +					  allow_non_xm, &non_xm_print,
>   					  baudrate, &baud_changed);
>   		if (rc)
>   			goto can;
> @@ -979,7 +985,8 @@ kwboot_xm_finish(int fd)
>   		if (rc)
>   			return rc;
>   
> -		rc = kwboot_xm_recv_reply(fd, &c, 0, NULL, 0, NULL);
> +		rc = kwboot_xm_recv_reply(fd, &c, retries < 3,
> +					  0, NULL, 0, NULL);
>   		if (rc)
>   			return rc;
>   	} while (c == NAK && retries++ < 16);
> 


Viele Grüße,
Stefan

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