On Fri 2018-09-21 22:59:40, Jacek Anaszewski wrote: > Hi Baolin, > > On 09/21/2018 05:31 AM, Baolin Wang wrote: > > Hi Jacek and Pavel, > > > > On 11 September 2018 at 10:47, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote: > >> This patch adds one new led trigger that LED device can configure > >> the software or hardware pattern and trigger it. > >> > >> Consumers can write 'pattern' file to enable the software pattern > >> which alters the brightness for the specified duration with one > >> software timer. > >> > >> Moreover consumers can write 'hw_pattern' file to enable the hardware > >> pattern for some LED controllers which can autonomously control > >> brightness over time, according to some preprogrammed hardware > >> patterns. > >> > >> Signed-off-by: Raphael Teysseyre <rteysseyre@xxxxxxxxx> > >> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> > > Do you have any comments for the v12 patch set? Thanks. > > We will probably have to remove hw_pattern from ledtrig-pattern > since we are unable to come up with generic interface for it. > Unless thread [0] will end up with some brilliant ideas. So far > we're waiting for Pavel's reply. > > [0] https://lkml.org/lkml/2018/9/13/1216 Patch 1/2 is not controversial; I believe we can apply it now. 2/2: Non-linear or not, can we just ignore that for now? We don't have well-defined meaning of what brightness 128 means, so... I believe we can do that reasonably safely. I don't exactly understand what you are saying with the four tuples. Yes, sc27xx currently has a limit where it can do single rise, hold, lower, hold at zero. That is described by pattern: "0 rise_duration brightness high_duration brightness fall_duration 0 low_duration" We should add this to sc27xx handler: > I'd actually like to see this at begining of function: > if (pattern[0].brightness != 0) > return -EINVAL; > if (pattern[2].brightness != 0) > return -EINVAL; > if (pattern[3].brightness != 0) > return -EINVAL; > if (pattern[1].brightness != pattern[2].brightness) > return -EINVAL; > > ..so if user writes something unexpected, he gets the error back. Then it is compatible -- or should be. Pattern trigger should do the same -- rise, hold, lower, hold at zero. I don't really see the problem. Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Attachment:
signature.asc
Description: Digital signature
