Re: [PATCH v4 3/3] usb: dwc3: Log dwc3 address in traces

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Jan 14, 2026 at 03:37:48PM +0530, Prashanth K wrote:
> When multiple DWC3 controllers are being used, trace events from
> different instances get mixed up making debugging difficult as
> there's no way to distinguish which instance generated the trace.
> 
> Use the register base address of dwc3 controller and append it to
> trace events, so that the source instance is clearly identifiable.
> 
> Example trace output,
> before ->  dwc3_event: event (00000101): Reset [U0]
> after  ->  dwc3_event: 0a600000: event (00000101): Reset [U0]
> 
> Signed-off-by: Prashanth K <prashanth.k@oss.qualcomm.com>
> ---
>  drivers/usb/dwc3/core.c   |  5 ++-
>  drivers/usb/dwc3/core.h   |  2 +
>  drivers/usb/dwc3/ep0.c    |  2 +-
>  drivers/usb/dwc3/gadget.c |  2 +-
>  drivers/usb/dwc3/io.h     |  4 +-
>  drivers/usb/dwc3/trace.h  | 88 ++++++++++++++++++++++++---------------
>  6 files changed, 65 insertions(+), 38 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 670a9d4bfff2..125616489e04 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -158,7 +158,7 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode, bool ignore_susphy)
>  	dwc3_writel(dwc, DWC3_GCTL, reg);
>  
>  	dwc->current_dr_role = mode;
> -	trace_dwc3_set_prtcap(mode);
> +	trace_dwc3_set_prtcap(dwc, mode);
>  }
>  EXPORT_SYMBOL_GPL(dwc3_set_prtcap);
>  
> @@ -2193,6 +2193,9 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
>  	dwc_res = *res;
>  	dwc_res.start += DWC3_GLOBALS_REGS_START;
>  
> +	/* Store the base register address for using it in traces later */
> +	dwc->address = (u32)res->start;

And shouldn't this be dwc_res.start?  Why ignore
DWC3_GLOBALS_REGS_START?

And because of that, shouldn't this go below:

> +
>  	if (dev->of_node) {
>  		struct device_node *parent = of_get_parent(dev->of_node);

That if statement, which will change the real resource start range
value?

thanks,

greg k-h