Re: [PATCH] xhci: Make debug message consistent with bus and port number

From: Greg Kroah-Hartman
Date: Thu May 07 2020 - 03:31:23 EST


On Thu, May 07, 2020 at 03:15:01PM +0800, Kai-Heng Feng wrote:
>
>
> > On May 7, 2020, at 14:45, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Thu, May 07, 2020 at 02:17:55PM +0800, Kai-Heng Feng wrote:
> >> Current xhci debug message doesn't always output bus number, so it's
> >> hard to figure out it's from USB2 or USB3 root hub.
> >>
> >> In addition to that, some port numbers are offset to 0 and others are
> >> offset to 1. Use the latter to match the USB core.
> >>
> >> So use "bus number - port index + 1" to make debug message consistent.
> >>
> >> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> >> ---
> >> drivers/usb/host/xhci-hub.c | 41 +++++++++++++++++++++----------------
> >> 1 file changed, 23 insertions(+), 18 deletions(-)
> >>
> >> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> >> index f37316d2c8fa..83088c262cc4 100644
> >> --- a/drivers/usb/host/xhci-hub.c
> >> +++ b/drivers/usb/host/xhci-hub.c
> >> @@ -1241,7 +1241,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
> >> temp = readl(ports[wIndex]->addr);
> >> /* Disable port */
> >> if (link_state == USB_SS_PORT_LS_SS_DISABLED) {
> >> - xhci_dbg(xhci, "Disable port %d\n", wIndex);
> >> + xhci_dbg(xhci, "Disable port %d-%d\n",
> >> + hcd->self.busnum, wIndex + 1);
> >
> > Shouldn't xhci_dbg() show the bus number already?
>
> It's the PCI bus number, different to USB2/USB3 root hub bus number...

But if this is using dev_dbg(), and it is, then you know how to look
that up by seeing where that device is in sysfs at that point in time.

So why add this again?

> > If not, please fix
> > that up there instead of having to add it to all messages "by hand".
>
> Not all xhci debug messages need roothub number in it.

Why pick these random ones? What makes these different?

Either all or none, be consistant please.

greg k-h