[PATCH 27/38] iio: pressure-core: st: Give some indication if device probing was successful

On Wednesday, September 11, 2013 3:30 AM Lee Jones wrote:

On Wed, 11 Sep 2013, Lars-Peter Clausen wrote:

quoted

On 09/11/2013 09:10 AM, Lee Jones wrote:

quoted

On Tue, 10 Sep 2013, Jonathan Cameron wrote:

quoted

Lee Jones [off-list ref] wrote:

Silence means everything is good, a message means there is an error.
If every device that gets probed would spit out a message the log
would be scrolling forever and you wouldn't be able to see the error
messages.

Only if you print out every regulator, clock, GPIO pin and things of this nature.
Key hardware blocks such as; SD, Flash, USB, Eth, HDMI, Audio, UART, GPIO and
I2C controllers and Sensors I think deserve a one line "I'm here and working"
message.

In many embedded systems -- there are lots and lots of IIO devices, and I'm not sure 
I would consider very many "key". It really depends on the board.

To me it's a matter of boot time. Even memcpy to msgbuf takes time.
Sometimes unnecessary time.

I'll not fight this for too long. This is based my experience as a user. I tried to
look at the bootlog for the sensors I'd just enabled and there was nothing. Some
of them had probed, some hadn't and there was no clear way to distinguish
between them without digging into sysfs.

echo "working:"
cat /sys/bus/iio/devices/*/name

isn't too much digging. If you really want to do that on your machine - do so in rc.local

for many other subsystems, it's just not that easy, and printing from the driver is necessary.

-Robin