On Tue, Dec 10, 2024 at 05:52:38PM +0000, Murthy, Arun R wrote: > > On Tue, Dec 10, 2024 at 08:42:36AM +0000, Murthy, Arun R wrote: > > > > On Mon, Dec 09, 2024 at 09:54:55PM +0530, Arun R Murthy wrote: > > > > > Add variables for histogram drm_property, its corrsponding > > > > > crtc_state variables and define the structure pointed by the blob property. > > > > > > > > > > struct drm_histogram and drm_iet defined in > > > > > include/uapi/drm/drm_mode.h > > > > > > > > > > The property HISTOGRAM_ENABLE allows user to enable/disable the > > > > > histogram feature in the hardware. Upon KMD enabling by writing to > > > > > the hardware registers, a histogram is generated. Histogram is > > > > > composed of 'n' bins with each bin being an integer(pixel count). > > > > > > > > Is it really a count of pixels that fall into one of the bins? > > > It's the statistics generated for each frame that is sent to the display and the > > value corresponds to 5 bit pixel depth. > > > > Let me try it once more, but this is becoming tiresome. Please provide a > > description of the property good enough so that one can implement > > HISTOGRAM support for the VKMS driver. You don't have to provide Intel- > > specific details, but the description should be complete enough. > > "The number of pixels falling into each of the bins, sorted by luminosity, started > > from the brighest ones" might be an example of a good enough desription. > > Then one can add such functionality to other drivers. Just saying "statistics" > > doesn't give us anything. > > > This is a hardware feature and hence for other drivers to add support for this > means that the hardware should have support for this. OpenGL, OpenGL ES, Vulkan and other libraries also define software interface for hardware features. However they define it in a way that allows at least software implementation. I'm not arguing about the particular feature or its implementation. I'm not asking for the _hardware_ description or any other kind hardware-related information. But I really want to see a good documentation for the userspace interface that will allows other vendors to implement it in their drivers (including my example, VKMS). Up to now I have not seen a definition of properties that fits this criteria. > Each bin consists of 5 bit pixel depth. > Example code of how to use this histogram and increase the contrast is GHE. Yes, I have taken a look. No, it's not a replacement for the documentation. I'm really sorry to write that, but until the documentation issue is resolved, please consider this patch to be: Nacked-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> > > Thanks and Regards, > Arun R Murthy > -------------------- -- With best wishes Dmitry
