[U-Boot] [PATCH 1/6] usb: legacy_hub_port_reset(): Speedup hub reset handling

[Hans de Goede]

Hi,

On 10-03-16 16:50, Stefan Roese wrote:
> Start with a short USB hub reset delay of 10ms. This can be enough for
> some configurations.
>
> The 2nd delay at the of the loop is completely removed. Since the delay
> hasn't been long enough, a longer delay time of 200ms is assigned. And
> will be used in the next loop round.
>
> This hub reset handling is also used in the v4.4 Linux USB driver,
> hub_port_reset().
>
> Signed-off-by: Stefan Roese <sr at denx.de>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Hans de Goede <hdegoede at redhat.com>
> Cc: Stephen Warren <swarren at nvidia.com>
> Cc: Marek Vasut <marex at denx.de>

Since this is good enough for the kernel it should be good enough for us:

Acked-by: Hans de Goede <hdegoede at redhat.com>

Regards,

Hans

> ---
>
>   common/usb_hub.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/common/usb_hub.c b/common/usb_hub.c
> index e1de813..10fdd3c 100644
> --- a/common/usb_hub.c
> +++ b/common/usb_hub.c
> @@ -46,6 +46,9 @@ DECLARE_GLOBAL_DATA_PTR;
>
>   #define USB_BUFSIZ	512
>
> +#define HUB_SHORT_RESET_TIME	10
> +#define HUB_LONG_RESET_TIME	200
> +
>   /* TODO(sjg at chromium.org): Remove this when CONFIG_DM_USB is defined */
>   static struct usb_hub_device hub_dev[USB_MAX_HUB];
>   static int usb_hub_index;
> @@ -164,6 +167,7 @@ int legacy_hub_port_reset(struct usb_device *dev, int port,
>   	int err, tries;
>   	ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
>   	unsigned short portstatus, portchange;
> +	int delay = HUB_SHORT_RESET_TIME; /* start with short reset delay */
>
>   #ifdef CONFIG_DM_USB
>   	debug("%s: resetting '%s' port %d...\n", __func__, dev->dev->name,
> @@ -176,7 +180,7 @@ int legacy_hub_port_reset(struct usb_device *dev, int port,
>   		if (err < 0)
>   			return err;
>
> -		mdelay(200);
> +		mdelay(delay);
>
>   		if (usb_get_port_status(dev, port + 1, portsts) < 0) {
>   			debug("get_port_status failed status %lX\n",
> @@ -215,7 +219,8 @@ int legacy_hub_port_reset(struct usb_device *dev, int port,
>   		if (portstatus & USB_PORT_STAT_ENABLE)
>   			break;
>
> -		mdelay(200);
> +		/* Switch to long reset delay for the next round */
> +		delay = HUB_LONG_RESET_TIME;
>   	}
>
>   	if (tries == MAX_TRIES) {
>