From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Pavel Machek <pavel@ucw.cz>, Dan Murphy <dmurphy@ti.com>,
Jiri Slaby <jslaby@suse.com>,
linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org,
linux-serial@vger.kernel.org, kernel@pengutronix.de
Subject: Re: [PATCH v2 3/3] leds: trigger: implement a tty trigger
Date: Tue, 17 Dec 2019 11:58:26 +0100 [thread overview]
Message-ID: <20191217105826.6d2odt4k5b4qknjk@pengutronix.de> (raw)
In-Reply-To: <20191217083211.GC2672708@kroah.com>
Hello Greg,
On Tue, Dec 17, 2019 at 09:32:11AM +0100, Greg Kroah-Hartman wrote:
> On Tue, Dec 17, 2019 at 09:17:18AM +0100, Uwe Kleine-König wrote:
> > + ret = tty_get_icount(trigger_data->tty, &icount);
> > + if (icount.rx > trigger_data->icount.rx ||
> > + icount.tx > trigger_data->icount.tx) {
>
> What happens when icount.rx and/or icount.tx wraps? It's "only" an int.
Good catch. I wonder why this is not an unsigned quantity. Just grepping
through drivers/tty/serial most drivers just increment these counters
and don't care for overflow (which is undefined for ints) either. :-\
..ooOO(Where is the can maintainer? --- We found a can of worms :-)
> > + unsigned long delay_on = 100, delay_off = 100;
> > +
> > + led_blink_set_oneshot(trigger_data->led_cdev,
> > + &delay_on, &delay_off, 0);
> > +
> > + trigger_data->icount = icount;
>
> Implicit memcpy of a structure? Ick.
I'd call that elegant ;-)
> All you care about are the two integers, why not just track them instead
> of the whole thing?
For now I only care about tx and rx, but I intend to add some bells and
whistles to trigger on other events. (But I don't care much, can add
that once I implement this support.)
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
next prev parent reply other threads:[~2019-12-17 10:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-17 8:17 [PATCH v2 0/3] tty/leds: implement a trigger for ttys Uwe Kleine-König
2019-12-17 8:17 ` [PATCH v2 1/3] tty: new helper function tty_kopen_shared Uwe Kleine-König
2019-12-17 8:27 ` Greg Kroah-Hartman
2019-12-17 10:51 ` Uwe Kleine-König
2019-12-17 11:05 ` Greg Kroah-Hartman
2019-12-17 8:17 ` [PATCH v2 2/3] tty: new helper function tty_get_icount() Uwe Kleine-König
2019-12-17 8:28 ` Greg Kroah-Hartman
2019-12-17 8:17 ` [PATCH v2 3/3] leds: trigger: implement a tty trigger Uwe Kleine-König
2019-12-17 8:32 ` Greg Kroah-Hartman
2019-12-17 10:58 ` Uwe Kleine-König [this message]
2019-12-17 11:07 ` Greg Kroah-Hartman
2019-12-17 8:32 ` [PATCH v2 0/3] tty/leds: implement a trigger for ttys Greg Kroah-Hartman
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