Re: [PATCH] usb: dwc3: core: Set force_gen1 bit for all applicable SuperSpeed ports

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Tue, Nov 12, 2024, Krishna Kurapati wrote:
> Currently if the maximum-speed is set to Super Speed for a 3.1 Gen2
> capable controller, the FORCE_GEN1 bit of LLUCTL register is set only
> for one SuperSpeed port (or the first port) present. Modify the logic
> to set the FORCE_GEN1 bit for all ports if speed is being limited to
> Gen-1.
> 
> Suggested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> ---
> Suggestion provided for the same at:
> https://urldefense.com/v3/__https://lore.kernel.org/all/20230517003037.i7hsg6k5fn4eyvgf@synopsys.com/__;!!A4F2R9G_pg!fxCYcGdwDaswO2QMGmJYPI2jJqusyiLy8LzeNmE9bgPoDMrwtEAjAIcGoKkQNUsuEF2ktPxCcoMawo3sSxCJBmlslgVv9g$ 
> 
> This patch has only been compile tested due to unavailability of
> hardware at the moment.
> 
>  drivers/usb/dwc3/core.c | 10 +++++++---
>  drivers/usb/dwc3/core.h |  2 +-
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 9b888d33e64d..67aefdbe1d5f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1470,9 +1470,13 @@ static int dwc3_core_init(struct dwc3 *dwc)
>  	if (hw_mode != DWC3_GHWPARAMS0_MODE_GADGET &&
>  	    (DWC3_IP_IS(DWC31)) &&
>  	    dwc->maximum_speed == USB_SPEED_SUPER) {
> -		reg = dwc3_readl(dwc->regs, DWC3_LLUCTL);
> -		reg |= DWC3_LLUCTL_FORCE_GEN1;
> -		dwc3_writel(dwc->regs, DWC3_LLUCTL, reg);
> +		int i;
> +
> +		for (i = 0; i < dwc->num_usb3_ports; i++) {
> +			reg = dwc3_readl(dwc->regs, DWC3_LLUCTL(i));
> +			reg |= DWC3_LLUCTL_FORCE_GEN1;
> +			dwc3_writel(dwc->regs, DWC3_LLUCTL(i), reg);
> +		}
>  	}
>  
>  	return 0;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index eaa55c0cf62f..296cbe85a494 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -179,7 +179,7 @@
>  #define DWC3_OEVTEN		0xcc0C
>  #define DWC3_OSTS		0xcc10
>  
> -#define DWC3_LLUCTL		0xd024
> +#define DWC3_LLUCTL(n)		(0xd024 + ((n) * 0x80))
>  
>  /* Bit fields */
>  
> -- 
> 2.34.1
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh