On Tuesday, September 1, 2020 3:26 PM, Daniel Vetter <[email protected]> wrote:
> On Tue, Sep 01, 2020 at 08:57:37AM +0000, Simon Ser wrote: > > > On Monday, August 31, 2020 3:48 PM, Ville Syrjälä > > [email protected] wrote: > > > > > > > It doesn't seem like this IGT test's goal is to exercise support for > > > > > gamma LUTs. Does the test just tries to reset the gamma LUT to linear? > > > > > If so, I think the IGT test should be fixed to ignore "I don't support > > > > > gamma" errors. > > > > > > > > It seems like that IGT test pixel-format is to make gamma lut like > > > > below. > > > > for (i = 0; i < lut_size; i++) > > > > lut[i] = (i * 0xffff / (lut_size - 1)) & mask; > > > > And set this table to drm driver. and test begins. It's the test about > > > > pixel > > > > format. I think you're right. It's not about gamma lut. > > > > > > The point of the gamma LUT stuff in the pixel format test is to throw > > > away a bunch of the lsbs so that the test passes when the result is > > > "close enough" to the 8bpc RGB reference image. Without it we would > > > never get a crc match when testing non-8bpc or YCbCr formats. > > > > OK, that makes sense. Would it be sensible to: > > > > - Don't set gamma if the pixel format being tested is 8bpc > > Hm not sure what 8bpc format you mean here, because we have C8 (needs > gamma table or doesn't work) and the 8b greyscale one with the R8 one. If > you ask for legacy 8bpc you get C8. Why do we need a gamma LUT for C8 and R8? There shouldn't be any precision loss, right? > > - Make the test skip if the pixel format is >8bpc and gamma isn't > > supported > > > > Yeah the test should skip if gamma isn't there. > -Daniel > > > dri-devel mailing list > > [email protected] > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > -- > > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
