Re: [PATCH v1] usb: core: Add boot delay for DH34 board in restore mode

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Mar 06, 2025 at 02:17:49PM +0800, Jiayi Li wrote:
> On certain DH34-model motherboards, USB keyboards may fail to respond
> during the restore mode confirmation prompt due to the usbhid driver
> not being fully initialized when device registration occurs. This
> results in inability to input 'y'/'n' confirmation.
> 
> Detect this scenario by:
> 1. Checking DMI_BOARD_NAME for "DH34" substring
> 2. Verifying "restore" in kernel command line
> 
> Introduce a 200ms delay before device registration when both conditions
> are met. This allows sufficient time for the usbhid driver to properly
> initialize before user interaction is required.
> 
> Signed-off-by: Jiayi Li <lijiayi@kylinos.cn>
> ---
>  drivers/usb/core/hub.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index a76bb50b6202..b81b518f438b 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -36,6 +36,7 @@
>  #include <linux/bitfield.h>
>  #include <linux/uaccess.h>
>  #include <asm/byteorder.h>
> +#include <linux/dmi.h>
>  
>  #include "hub.h"
>  #include "phy.h"
> @@ -2610,6 +2611,7 @@ static void set_usb_port_removable(struct usb_device *udev)
>  int usb_new_device(struct usb_device *udev)
>  {
>  	int err;
> +	const char *board_name;
>  
>  	if (udev->parent) {
>  		/* Initialize non-root-hub device wakeup to disabled;
> @@ -2656,6 +2658,17 @@ int usb_new_device(struct usb_device *udev)
>  	/* check whether the hub or firmware marks this port as non-removable */
>  	set_usb_port_removable(udev);
>  
> +	/* get board manufacturer information (DMI_BOARD_VENDOR) */
> +	board_name = dmi_get_system_info(DMI_BOARD_NAME);

What about platforms that do not have DMI?

> +
> +	/* In order to load the usbhid driver on a specific model motherboards
> +	 * before the restore mode confirmation, add 200ms of latancy.
> +	 */
> +	if (board_name && strstr(board_name, "DH34") &&
> +		(strstr(saved_command_line, "restore") != NULL))
> +		msleep(200);
> +
> +

Always use scripts/checkpatch.pl before sending patches out.

thanks,

greg k-h