[PATCH] usb: kbd: dwc2: Increase wait for dwc2 controller reset by 125us

[Marek Vasut]

On 5/15/23 16:53, Filip Zaludek wrote:
> Two following performance patches applied together occasionally harm usb keyboard on RPi3.
> 
> 'dwc2: use the nonblock argument in submit_int_msg'
> commit 9dcab2c4d2cb50ab1864c818b82a72393c160236
> 
> 'console: usb: kbd: Limit poll frequency to improve performance'
> commit 96991e652f541323a03c5b7e075d54a117091618
> 
> This empirically increased by sub-millisecond wait for dwc2 controller reset makes
> keyboard reliable.
> 
> Signed-off-by: Filip Zaludek <filip.zaludek at oracle.com>
> ---
>   drivers/usb/host/dwc2.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
> index 23060fc369..71b66a52ed 100644
> --- a/drivers/usb/host/dwc2.c
> +++ b/drivers/usb/host/dwc2.c
> @@ -764,7 +764,7 @@ static int dwc_otg_submit_rh_msg_out(struct dwc2_priv *priv,
>   					DWC2_HPRT0_PRTENCHNG |
>   					DWC2_HPRT0_PRTOVRCURRCHNG,
>   					DWC2_HPRT0_PRTRST);
> -			mdelay(50);
> +			udelay(50125);

Why not just use 'mdelay(51);' ?

If you can tell me how to reproduce this , I could try and use USB bus 
analyzer (Beagle 5000) to look at his. I have RPi3 somewhere I think. 
Then we would know what's up.

But that might take a while, since I am a bit busy these days.