On Wed, Jul 06, 2016 at 05:22:40PM +0200, Arnd Bergmann wrote:

On Monday, July 4, 2016 5:50:09 PM CEST Uwe Kleine-König wrote:

quoted

On Mon, Jul 04, 2016 at 05:43:03PM +0200, Arnd Bergmann wrote:

quoted

On Monday, July 4, 2016 5:34:12 PM CEST Uwe Kleine-König wrote:

quoted

Add support for two led triggers per UART instance that blink on
transmission and reception of data respectively.

Signed-off-by: Uwe Kleine-König <redacted>
---
 drivers/tty/serial/imx.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

What is specific to this driver here? Could this be done in the
core tty code instead?

The core doesn't notice when the driver starts to push out characters.

I also have a patch in my queue that adds support for rts delaying in
rs485 mode. While the delay between start_tx being called and the first
char leaving the hardware might not be big enough to care in rs232 mode,
with a big delay_rts_before_send it might matter.

Right, that makes sense. It still seems odd to have this just in one
driver, and your changelog above doesn't really explain what the
blinkenlights are actually good for.

I'm sure you had something useful in mind, can you elaborate?

I don't know the exact motivation. $customer wants to see when there is
traffic on the serial line. Is there a better motivation needed? If so,
what was the motivation for the mmc led trigger (which btw also used the
host's device name as trigger name).

If this is something we may want to do on other platforms as well,
we should perhaps not hardwire the name of the imx tty device in
the led trigger name.

I cannot follow. If we have several serial lines and a trigger for each
of them, they must get different names. Using the device's name to
distinguish them seems like a good and obvious idea.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |