Regards Shashank
On 8/4/2016 5:04 PM, Emil Velikov wrote: > On 4 August 2016 at 11:16, Sharma, Shashank <shashank.sharma at intel.com> > wrote: >> Hello Emil, >> >> Thanks for your time. >> >> I have got mixed opinion on this. >> >> IMHO we should expose them to userspace too, as UI agents like Hardware >> composer/X/Wayland must know what does these >> >> flags means, so that they can display them on the end user screen (like >> settings menu) >> >> But few people even think thats its too complex to be exposed to userspace >> agents. >> > If we want these/such flags passed between kernel and user space one must: > - Provide a kernel interface how to do that > - Provide a userspace (acked by respective developers/maintainers) > that the approach is sane and proves useful. > > Since the above can take some time, I'd suggest dropping those from > the UAPI header(s)... for now. > > -Emil Please guide me a bit more on this problem, Emil, Daniel. The reason why I want to pass this to userspace is, so that, HWC/X/any other UI manager, can send a modeset which is accurate upto aspect ratio. Please think of this complete scenario: - HDMI compliance testing is going on, and we need to apply a CEA mode (for example, VIC=3, mode - 720x480 at 60Hz aspect 16:9) - But HWC doesnt pass the aspect ratio information, and passed only 720x480 at 60Hz - Kernel gets the first matching mode, from edid_cea_modes, which is VIC=2 720x480 at 60Hz (aspect 4:3) - Kernel does the modeset of VIC = 2, and AVI IF contain VIC=2 - Compliance equipment expects VIC = 3, so fails the test case. In this case, its essential that the userspace, which is triggering the modeset, must know about the aspect ratio field too. So does this make it a reason to pass this information to usp ? Regards Shashank
