Re: [PATCH 2/2] xhci:prevent "callbacks suppressed" when debug isnot enabled

From: Greg KH
Date: Fri Aug 16 2013 - 13:45:25 EST


On Fri, Aug 16, 2013 at 08:38:12PM +0300, Dmitry Kasatkin wrote:
> On Fri, Aug 16, 2013 at 8:30 PM, Sarah Sharp <sarah.a.sharp@xxxxxxxxx> wrote:
> > On Fri, Aug 16, 2013 at 10:26:35AM -0700, Sarah Sharp wrote:
> >> On Thu, Aug 15, 2013 at 05:17:16PM -0700, Greg KH wrote:
> >> > On Thu, Aug 15, 2013 at 07:04:55PM +0300, Dmitry Kasatkin wrote:
> >> > > When debug is not enabled and dev_dbg() will expand to nothing,
> >> > > log might be flooded with "callbacks suppressed". If it was not
> >> > > done on purpose, better to use dev_dbg_ratelimited() instead.
> >> > >
> >> > > Signed-off-by: Dmitry Kasatkin <d.kasatkin@xxxxxxxxxxx>
> >> > > ---
> >> > > drivers/usb/host/xhci-ring.c | 6 ++----
> >> > > 1 file changed, 2 insertions(+), 4 deletions(-)
> >> >
> >> >
> >> > Sarah, does this patch conflict with the trace debug patches being
> >> > worked on? I'll hold off on applying it for now, let me know if it's ok
> >> > or not.
> >>
> >> It doesn't conflict with the trace debug patches, because those only
> >> effect debugging with xhci_dbg with the host device, not dev_dbg with
> >> the USB device. This should apply fine to usb-next.
> >
> > At another glance, the patch removes two if blocks, but doesn't
> > re-indent the rest of the lines:
> >
> >> @@ -3060,8 +3060,7 @@ int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
> >> * to set the polling interval (once the API is added).
> >> */
> >> if (xhci_interval != ep_interval) {
> >> - if (printk_ratelimit())
> >> - dev_dbg(&urb->dev->dev, "Driver uses different interval"
> >> + dev_dbg_ratelimited(&urb->dev->dev, "Driver uses different interval"
> >> " (%d microframe%s) than xHCI "
> >> "(%d microframe%s)\n",
> >> ep_interval,
> >
> > That should probably be fixed.
>
> It actually looks correct when patch is applied.
>
> But it depends what you mean of course.
> It looks like it was before:
> dev_dbg_ratelimited(&urb->dev->dev, "Driver uses different interval"
> " (%d microframe%s) than xHCI "
> "(%d microframe%s)\n",
> ep_interval,
> ep_interval == 1 ? "" : "s",
>
> Or may be you mean:
> dev_dbg_ratelimited(&urb->dev->dev, "Driver uses different interval"
> " (%d microframe%s) than xHCI "
> "(%d microframe%s)\n",
> ep_interval,
> ep_interval == 1 ? "" : "s",

No, it should look like:

dev_dbg_ratelimited(&urb->dev->dev,
"Driver uses different interval (%d microframe%s) than xHCI (%d microframe%s)\n",
ep_interval, ep_interval == 1 ? "" : "s",

and the rest of that call indented the same way.

thanks,

greg k-h
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