[U-Boot] [PATCH v6 1/2] console: usb: kbd: To improve TFTP booting performance

[Wolfgang Denk <wd@denx.de>]

Dear Jim Lin,

In message <1374156931-1718-1-git-send-email-jilin@nvidia.com> you wrote:
> TFTP booting is slow when a USB keyboard is installed and
> stdin has usbkbd added.
> This fix is to change Ctrl-C polling for USB keyboard to every second
> when NET transfer is running.
> 
> Signed-off-by: Jim Lin <jilin@nvidia.com>

The sequence of your patches is wrong; you must reverse it: as is,
with only patch 1/2 applied, you will get compile errors because
net_busy_flag is undefined.  This breaks bisectability.

Please switch the order of your patches.


> +	/*
> +	 * If net_busy_flag is 1, NET transfer is running,
> +	 * then we check key pressed every second to improve
> +	 * TFTP booting performance.
> +	 */
> +	if (net_busy_flag) {
> +		if (get_timer(kbd_testc_tms) < CONFIG_SYS_HZ)
> +			return 0;
> +		else
> +			kbd_testc_tms = get_timer(0);
> +	}

When first entering this code, the variable kbd_testc_tms is
(implicitly) initialized as zero;  later, for example when running
multiple network commands, the last used value (i. e. a random number)
is used.  So strictly speaking the comment above is incorrect, as you
don't test for key presses "every second" - the first test may happen
much earlier (even immediately).  I think this should be explained in
the comment to prevent incorrect expectations on the behaviour.



Best regards,

Wolfgang Denk

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