On 02/20/2015 04:36 PM, Greg KH wrote:
On Fri, Feb 20, 2015 at 08:56:11AM +0100, Jacek Anaszewski wrote:
On 02/19/2015 10:40 PM, Greg KH wrote:
On Thu, Feb 19, 2015 at 11:02:04AM +0200, Sakari Ailus wrote:
On Wed, Feb 18, 2015 at 11:47:47PM +0100, Pavel Machek wrote:
On Wed 2015-02-18 17:20:22, Jacek Anaszewski wrote:
Add a documentation of LED Flash class specific sysfs attributes.
Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
NAK-ed-by: Pavel Machek
+What: /sys/class/leds/<led>/available_sync_leds
+Date: February 2015
+KernelVersion: 3.20
+Contact: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
+Description: read/write
+ Space separated list of LEDs available for flash strobe
+ synchronization, displayed in the format:
+
+ led1_id.led1_name led2_id.led2_name led3_id.led3_name etc.
Multiple values per file, with all the problems we had in /proc. I
assume led_id is an integer? What prevents space or dot in led name?
Very good point. How about using a newline instead? That'd be a little bit
easier to parse, too.
No, please make it one value per-file, which is what sysfs requires.
The purpose of this attribute is only to provide an information about
the range of valid identifiers that can be written to the
flash_sync_strobe attribute. Wouldn't splitting this to many attributes
be an unnecessary inflation of sysfs files?
Ok a list of allowed values to write is acceptable, as long as it is not
hard to parse and always is space separated.
Is a new line character also acceptable as a delimiter?
Apart from it, we have also flash_faults attribute, that currently
provides a space separated list of flash faults that have occurred.
That's crazy, what's to keep it from growing and growing to be larger
than is allowed to be read?
The number of possible faults is fixed to 9 currently. They are
presented in the form of strings no longer currently than 40 characters.
There can be maximum 9 faults reported at a time, this is not a kind of
a log. This will allow to define roughly 100 types of faults, having
that PAGE_SIZE is 4096. I think this is far more than it is conceivable
for the simple LED flash device.
If we are to stick tightly to the one-value-per-file rule, then how
we should approach flash_faults case? Should the separate file be
dynamically created for each reported fault?
I think you need to use something other than sysfs here, sorry.
uevents for your faults?
thanks,
greg k-h
--
Best Regards,
Jacek Anaszewski
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