[U-Boot] [PATCH v4 1/1] NET: Improve TFTP booting performance when CONFIG_USB_KEYBOARD

[Wolfgang Denk]

Dear Jim Lin,

In message <1372847667-31928-1-git-send-email-jilin at nvidia.com> you wrote:
> TFTP booting is slow when a USB keyboard is installed and
> CONFIG_USB_KEYBOARD is defined.
> The fix is to change Ctrl-C polling to every second when NET transfer
> is running.

I'm not sure if we can accept this implementation.

> +#ifdef CONFIG_USB_KEYBOARD
> +		/*
> +		 * Reduce ctrl-c checking to 1 second once
> +		 * to improve TFTP boot performance.
> +		 */
> +		ctrlc_t = get_timer(kbd_ctrlc_tms);
> +		if (ctrlc_t > CONFIG_SYS_HZ) {
> +			ctrlc_result = ctrlc();
> +			kbd_ctrlc_tms = get_timer(0);
> +		} else {
> +			ctrlc_result = 0;
> +		}
> +		if (ctrlc_result) {
> +#else

get_timer() is used by a number of network related services.  For
information, just grep for it in the net/ and drivers/net/
directories.  The "get_timer(0)" used in your code resets a global
resource, and has thus the potential of messing up a number of
timeouts running elsewhere in the network code.  I wonder to which
extend this has actually been considered (and tested) ?

Best regards,

Wolfgang Denk

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