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From: Kent Gibson <warthog618@gmail.com>
To: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH v2 05/18] gpiolib: cdev: support GPIO_GET_LINE_IOCTL and GPIOLINE_GET_VALUES_IOCTL
Date: Sun, 2 Aug 2020 17:32:42 +0800
Message-ID: <20200802093242.GA23877@sol> (raw)
In-Reply-To: <20200802033158.GA13174@sol>

On Sun, Aug 02, 2020 at 11:31:58AM +0800, Kent Gibson wrote:
> On Fri, Jul 31, 2020 at 06:05:10PM +0200, Bartosz Golaszewski wrote:
> > On Sun, Jul 26, 2020 at 3:12 AM Kent Gibson <warthog618@gmail.com> wrote:
> > >
> > 
> > > >
> > > > > +               dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
> > > > > +                       offset);
> > > >
> > > > Perhaps tracepoint / event?
> > > >
> > >
> > > Again, a cut-and-paste from V1, and I have no experience with
> > > tracepoints or events, so I have no opinion on that.
> > >
> > > So, yeah - perhaps?
> > >
> > 
> > I think it's a good idea to add some proper instrumentation this time
> > other than much less reliable logs. Can you take a look at
> > include/trace/events/gpio.h? Adding new GPIO trace events should be
> > pretty straightforward by copy-pasti... drawing inspiration from
> > existing ones.
> > 
> 
> You only want tracepoints to replace those dev_dbg()s, so when a line
> is requested? What about the release?  Any other points?
> 

Had a closer look and it seems to me that the correct place to add such
tracepoints would be gpiod_request() and gpiod_free(), so they catch all
requests, not just the cdev ones.  And that moves it outside the scope
of this patch.

I personally don't have any use for the dev_dbg()s here and am happy to
remove them - they were only there to match the behaviour of
linehandle_create as closely as possible.

Cheers,
Kent.

  reply index

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-25  4:19 [PATCH v2 00/18] gpio: cdev: add uAPI V2 Kent Gibson
2020-07-25  4:19 ` [PATCH v2 01/18] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Kent Gibson
2020-07-25  4:19 ` [PATCH v2 02/18] gpio: uapi: define uAPI v2 Kent Gibson
2020-08-04 17:42   ` Bartosz Golaszewski
2020-08-05  5:18     ` Kent Gibson
2020-08-05 17:47       ` Bartosz Golaszewski
2020-08-06  1:03         ` Kent Gibson
2020-08-06  1:15       ` Kent Gibson
2020-08-06 15:53         ` Bartosz Golaszewski
2020-07-25  4:19 ` [PATCH v2 03/18] gpiolib: make cdev a build option Kent Gibson
2020-07-25 20:29   ` Andy Shevchenko
2020-07-26 22:25   ` Linus Walleij
2020-07-27  1:46     ` Kent Gibson
2020-07-27  5:57       ` Kent Gibson
2020-07-27  8:15         ` Linus Walleij
2020-07-25  4:19 ` [PATCH v2 04/18] gpiolib: add build option for CDEV v1 ABI Kent Gibson
2020-07-25  4:19 ` [PATCH v2 05/18] gpiolib: cdev: support GPIO_GET_LINE_IOCTL and GPIOLINE_GET_VALUES_IOCTL Kent Gibson
2020-07-25 20:51   ` Andy Shevchenko
2020-07-26  1:12     ` Kent Gibson
2020-07-26  3:24       ` Kent Gibson
2020-07-29  2:28       ` Kent Gibson
2020-07-29  8:05         ` Andy Shevchenko
2020-07-29 10:01           ` Kent Gibson
2020-07-31 16:05       ` Bartosz Golaszewski
2020-08-02  3:31         ` Kent Gibson
2020-08-02  9:32           ` Kent Gibson [this message]
2020-08-03 19:59             ` Bartosz Golaszewski
2020-08-03 20:02           ` Bartosz Golaszewski
2020-08-03 23:01             ` Kent Gibson
2020-08-04 17:47               ` Bartosz Golaszewski
2020-08-05  3:06                 ` Kent Gibson
2020-07-25  4:19 ` [PATCH v2 06/18] gpiolib: cdev: support GPIO_GET_LINEINFO_V2_IOCTL and GPIO_GET_LINEINFO_WATCH_V2_IOCTL Kent Gibson
2020-07-25  4:19 ` [PATCH v2 07/18] gpiolib: cdev: support edge detection for uAPI v2 Kent Gibson
2020-08-04 19:28   ` Bartosz Golaszewski
2020-07-25  4:19 ` [PATCH v2 08/18] gpiolib: cdev: support GPIOLINE_SET_CONFIG_IOCTL Kent Gibson
2020-07-25  4:19 ` [PATCH v2 09/18] gpiolib: cdev: support GPIOLINE_SET_VALUES_IOCTL Kent Gibson
2020-07-25  4:19 ` [PATCH v2 10/18] gpiolib: cdev: support setting debounce Kent Gibson
2020-07-25  4:19 ` [PATCH v2 11/18] gpio: uapi: document uAPI v1 as deprecated Kent Gibson
2020-08-04 19:43   ` Bartosz Golaszewski
2020-07-25  4:19 ` [PATCH v2 12/18] tools: gpio: port lsgpio to v2 uAPI Kent Gibson
2020-07-25  4:19 ` [PATCH v2 13/18] tools: gpio: port gpio-watch " Kent Gibson
2020-07-25  4:19 ` [PATCH v2 14/18] tools: gpio: rename nlines to num_lines Kent Gibson
2020-07-25  4:19 ` [PATCH v2 15/18] tools: gpio: port gpio-hammer to v2 uAPI Kent Gibson
2020-07-25  4:19 ` [PATCH v2 16/18] tools: gpio: port gpio-event-mon " Kent Gibson
2020-07-25  4:19 ` [PATCH v2 17/18] tools: gpio: add debounce support to gpio-event-mon Kent Gibson
2020-07-25  4:19 ` [PATCH v2 18/18] tools: gpio: add multi-line monitoring " Kent Gibson

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