[U-Boot] [PATCH v8 RESEND 2/2] console: usb: kbd: To improve TFTP booting performance

[Marek Vasut <marex@denx.de>]

Dear Jim Lin,

> 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>
> ---
> Changes in v2:
>  1. Change configuration name from CONFIG_CTRLC_POLL_MS to
> CONFIG_CTRLC_POLL_S. 2. New code will be executed only when
> CONFIG_CTRLC_POLL_S is defined in configuration header file.
>  3. Add description in README.console.
> Changes in v3:
>  1. Move changes to common/usb_kbd.c and doc/README.usb
>  2. Rename config setting to CONFIG_USBKB_TESTC_PERIOD.
>  3. Remove slow response on USB-keyboard input when TFTP boot is not
> running. Changes in v4:
>  1. Remove changes in doc/README.usb, common/usb_kbd.c and
>     CONFIG_USBKB_TESTC_PERIOD
>  2. Modify net/net.c
> Changes in v5:
>  1. Change variable name to ctrlc_t_start.
>  2. Use two calls of get_timer(0) to get time gap.
> Changes in v6:
>  1. In common/usb_kbd.c, check net_busy_flag to determine whether we poll
>     USB keyboard status.
>  2. In include/usb.h, add external variable declaration net_busy_flag
> Changes in v7:
>  1. In common/usb_kbd.c and include/usb.h, add #ifdef CONFIG_CMD_NET.
>  2. In common/usb_kbd.c, modify code to get correct time gap.
> Changes in v8:
>  1. Add __maybe_unused for variable kbd_testc_tms.
> 
>  common/usb_kbd.c |   13 +++++++++++++
>  include/usb.h    |    2 +-
>  2 files changed, 14 insertions(+), 1 deletions(-)
> 
> diff --git a/common/usb_kbd.c b/common/usb_kbd.c
> index 3174b5e..4e7b304 100644
> --- a/common/usb_kbd.c
> +++ b/common/usb_kbd.c
> @@ -121,6 +121,9 @@ struct usb_kbd_pdata {
>  	uint8_t		flags;
>  };
> 
> +/* The period of time between two calls of usb_kbd_testc(). */
> +static unsigned long __maybe_unused kbd_testc_tms;
> +
>  /* Generic keyboard event polling. */
>  void usb_kbd_generic_poll(void)
>  {
> @@ -366,6 +369,16 @@ static int usb_kbd_testc(void)
>  	struct usb_device *usb_kbd_dev;
>  	struct usb_kbd_pdata *data;
> 
> +#ifdef CONFIG_CMD_NET
> +	/*
> +	 * If net_busy_flag is 1, NET transfer is running,
> +	 * then we check key-pressed every second (first check may be
> +	 * less than 1 second) to improve TFTP booting performance.
> +	 */
> +	if (net_busy_flag && (get_timer(kbd_testc_tms) < CONFIG_SYS_HZ))
> +		return 0;
> +	kbd_testc_tms = get_timer(0);
> +#endif
>  	dev = stdio_get_by_name(DEVNAME);
>  	usb_kbd_dev = (struct usb_device *)dev->priv;
>  	data = usb_kbd_dev->privptr;
> diff --git a/include/usb.h b/include/usb.h
> index d7b082d..5c95bf5 100644
> --- a/include/usb.h
> +++ b/include/usb.h
> @@ -206,7 +206,7 @@ int usb_host_eth_scan(int mode);
> 
>  int drv_usb_kbd_init(void);
>  int usb_kbd_deregister(void);
> -
> +extern int __maybe_unused net_busy_flag;

I wonder what would happen if you declared it here as

static int __maybe_unused

Would it have some side-effects?

>  #endif
>  /* routines */
>  int usb_init(void); /* initialize the USB Controller */

Othewise,

Acked-by: Marek Vasut <marex@denx.de>

Best regards,
Marek Vasut