Re: [PATCH 1/4] usb: cdns3: gadget: Replace trace_printk by dev_dbg

From: Felipe Balbi <balbi@kernel.org>
To: Nicolas Boichat <drinkcat@chromium.org>
Cc: Peter Chen <peter.chen@nxp.com>,
	"Guilherme G . Piccoli" <gpiccoli@canonical.com>,
	Rafael Aquini <aquini@redhat.com>,
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	Christian Brauner <christian.brauner@ubuntu.com>,
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	devel@driverdev.osuosl.org,
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	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Jayshri Pawar <jpawar@cadence.com>,
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Subject: Re: [PATCH 1/4] usb: cdns3: gadget: Replace trace_printk by dev_dbg
Date: Fri, 24 Jul 2020 10:53:36 +0300	[thread overview]
Message-ID: <87365hnybj.fsf@kernel.org> (raw)
In-Reply-To: <CANMq1KDugXcmvrGOJzcvWvbzScPDsQVuJ4gSDXTJan+FY1H3Ew@mail.gmail.com>

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Nicolas Boichat <drinkcat@chromium.org> writes:

> On Thu, Jul 23, 2020 at 9:17 PM Felipe Balbi <balbi@kernel.org> wrote:
>>
>> Nicolas Boichat <drinkcat@chromium.org> writes:
>>
>> > trace_printk should not be used in production code, replace it
>> > call with dev_dbg.
>> >
>> > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
>> >
>> > ---
>> >
>> > Unclear why a trace_printk was used in the first place, it's
>> > possible that some rate-limiting is necessary here.
>> >
>> >  drivers/usb/cdns3/gadget.c | 2 +-
>> >  1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>> > index 5e24c2e57c0d8c8..c303ab7c62d1651 100644
>> > --- a/drivers/usb/cdns3/gadget.c
>> > +++ b/drivers/usb/cdns3/gadget.c
>> > @@ -421,7 +421,7 @@ static int cdns3_start_all_request(struct cdns3_device *priv_dev,
>> >               if ((priv_req->flags & REQUEST_INTERNAL) ||
>> >                   (priv_ep->flags & EP_TDLCHK_EN) ||
>> >                       priv_ep->use_streams) {
>> > -                     trace_printk("Blocking external request\n");
>> > +                     dev_dbg(priv_dev->dev, "Blocking external request\n");
>>
>> Instead, I would suggest adding a proper trace event here; one that
>> includes "priv_ep->flags" in the output.
>
> The patch was already merged by Greg
> (https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/usb/cdns3/gadget.c?id=b3a5ce874c2619c9b8a6c5bbcfefdb95e0227600),
> but feel free to do that as a follow-up CL.
>
> Looks like Peter -- the main author, is ok with dev_dbg (also,
> apologies for missing the R-b tag when I sent a v2 -- which is the one
> that was merged by Greg).

That's okay, we can get a proper trace event for v5.10. Maybe Pawel or
Roger would like to take the effort?

-- 
balbi

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