From: Johan Hovold <johan@kernel.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: linux-serial@vger.kernel.org,
One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
Florian Fainelli <f.fainelli@gmail.com>,
Pavel Machek <pavel@ucw.cz>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, kernel@pengutronix.de,
linux-arm-kernel@lists.infradead.org,
Robin Murphy <robin.murphy@arm.com>
Subject: Re: [PATCH v2] tty: implement led triggers
Date: Mon, 7 May 2018 10:02:52 +0200 [thread overview]
Message-ID: <20180507080252.GO2285@localhost> (raw)
In-Reply-To: <20180503201952.16592-1-u.kleine-koenig@pengutronix.de>
On Thu, May 03, 2018 at 10:19:52PM +0200, Uwe Kleine-König wrote:
> The rx trigger fires when data is pushed to the ldisc. This is a bit later
> than the actual receiving of data but has the nice benefit that it
> doesn't need adaption for each driver and isn't in the hot path.
>
> Similarily the tx trigger fires when data taken from the ldisc.
You meant copied from user space, or written to the ldisc, here.
Note that the rx-path is shared with serdev, but the write path is not.
So with this series, serdev devices would only trigger the rx-led.
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> Changes since v1, sent with Message-Id:
> 20180503100448.1350-1-u.kleine-koenig@pengutronix.de:
>
> - implement tx trigger;
> - introduce Kconfig symbol for conditional compilation;
> - set trigger to NULL if allocating the name failed to not free random
> pointers in case the port struct wasn't zeroed;
> - use if/else instead of goto
> @@ -499,6 +500,7 @@ static void flush_to_ldisc(struct work_struct *work)
> struct tty_buffer *head = buf->head;
> struct tty_buffer *next;
> int count;
> + unsigned long delay = 50 /* ms */;
Comment after the semicolon?
>
> /* Ldisc or user is trying to gain exclusive access */
> if (atomic_read(&buf->priority))
> diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
> index 25d736880013..f042879a597c 100644
> --- a/drivers/tty/tty_port.c
> +++ b/drivers/tty/tty_port.c
> @@ -16,6 +16,7 @@
> #include <linux/wait.h>
> #include <linux/bitops.h>
> #include <linux/delay.h>
> +#include <linux/leds.h>
> #include <linux/module.h>
> #include <linux/serdev.h>
>
> @@ -157,6 +158,30 @@ struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
>
> tty_port_link_device(port, driver, index);
>
> +#ifdef CONFIG_TTY_LEDS_TRIGGER
> + port->led_trigger_rx_name = kasprintf(GFP_KERNEL, "%s%d-rx",
> + driver->name, index);
> + if (port->led_trigger_rx_name) {
> + led_trigger_register_simple(port->led_trigger_rx_name,
> + &port->led_trigger_rx);
> + } else {
> + port->led_trigger_rx = NULL;
> + pr_err("Failed to allocate trigger name for %s%d\n",
> + driver->name, index);
> + }
> +
> + port->led_trigger_tx_name = kasprintf(GFP_KERNEL, "%s%d-tx",
> + driver->name, index);
> + if (port->led_trigger_tx_name) {
> + led_trigger_register_simple(port->led_trigger_tx_name,
> + &port->led_trigger_tx);
> + } else {
> + port->led_trigger_tx = NULL;
> + pr_err("Failed to allocate trigger name for %s%d\n",
> + driver->name, index);
> + }
> +#endif
Besides the ugly ifdefs here, you're leaking the above LED resources in
the error paths below (e.g. on probe deferrals).
> dev = serdev_tty_port_register(port, device, driver, index);
> if (PTR_ERR(dev) != -ENODEV) {
> /* Skip creating cdev if we registered a serdev device */
> @@ -249,6 +249,13 @@ struct tty_port {
> set to size of fifo */
> struct kref kref; /* Ref counter */
> void *client_data;
> +
> +#ifdef CONFIG_TTY_LEDS_TRIGGER
> + struct led_trigger *led_trigger_rx;
> + char *led_trigger_rx_name;
const?
> + struct led_trigger *led_trigger_tx;
> + char *led_trigger_tx_name;
ditto.
> +#endif
Johan
next prev parent reply other threads:[~2018-05-07 8:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-03 10:04 [PATCH] tty: implement a rx led trigger Uwe Kleine-König
2018-05-03 10:10 ` Pavel Machek
2018-05-03 11:52 ` Uwe Kleine-König
2018-05-03 12:33 ` Robin Murphy
2018-05-03 20:19 ` [PATCH v2] tty: implement led triggers Uwe Kleine-König
2018-05-04 0:29 ` kbuild test robot
2018-05-07 8:02 ` Johan Hovold [this message]
2018-05-07 8:41 ` Uwe Kleine-König
2018-05-07 9:27 ` Johan Hovold
2018-05-10 11:14 ` Pavel Machek
2018-05-10 11:25 ` Robin Murphy
2018-05-12 19:00 ` Uwe Kleine-König
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180507080252.GO2285@localhost \
--to=johan@kernel.org \
--cc=f.fainelli@gmail.com \
--cc=gnomes@lxorguk.ukuu.org.uk \
--cc=gregkh@linuxfoundation.org \
--cc=kernel@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=mathieu.poirier@linaro.org \
--cc=pavel@ucw.cz \
--cc=robin.murphy@arm.com \
--cc=u.kleine-koenig@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).