On 2018-06-06 01:03 PM, Michel Dänzer wrote: > On 2018-06-06 06:01 PM, Michel Dänzer wrote: >> On 2018-06-01 06:03 PM, sunpeng.li at amd.com wrote: >>> From: "Leo (Sunpeng) Li" <sunpeng.li at amd.com> >>> >>> This ended up being different enough from v2 to warrant a new patchset. Per >>> Michel's suggestions, there have been various optimizations and cleanups. >>> Here's what's changed: >>> >>> * Cache DRM color management property IDs at pre-init, >>> * instead of querying DRM each time we need to modify color properties. >>> >>> * Remove drmmode_update_cm_props(). >>> * Update color properties in drmmode_output_get_property() instead. >>> * This also makes old calls to update_cm_props redundant. >>> >>> * Get rid of fake CRTCs. >>> * Previously, we were allocating a fake CRTC to configure color props on >>> outputs that don't have a CRTC. >>> * Instead, rr_configure_and_change_cm_property() can be easily modified to >>> accept NULL CRTCs. >>> >>> * Drop patches to persist color properties across DPMS events. >>> * Kernel driver should be patched instead: >>> https://lists.freedesktop.org/archives/amd-gfx/2018-May/022744.html >>> * Color props including legacy gamma now persist across crtc dpms. >>> * Non-legacy props now persist across output dpms and hotplug, as long >>> as the same CRTC remains attached to that output. >>> >>> And some smaller improvements: >>> >>> * Change CTM to be 32-bit format instead of 16-bit. >>> * This requires clients to ensure that each 32-bit element is padded to be >>> long-sized, since libXrandr parses 32-bit format as long-typed. >>> >>> * Optimized color management init during CRTC init. >>> * Query DRM once for the list of properties, instead of twice. >> >> Sounds good. I'll be going through the patches in detail from now on, >> but I don't know yet when I'll be able to finish the review. >> >> >> Meanwhile, heads up on two issues I discovered while smoke-testing the >> series (which are sort of related, but occur even without this series): >> >> >> Running Xorg in depth 30[0] results in completely wrong colours >> (everything has a red tint) with current kernels. I think this is >> because DC now preserves the gamma LUT values, but xf86-video-amdgpu >> never sets them at depth 30, so the hardware is still using values for >> 24-bit RGB. > > Actually, looks like I made a mistake in my testing before; this issue > only occurs as of patch 6 of this series. > It seems to be caused by legacy gamma being disabled on depth 30. When that's the case, the gamma_set() hook is set to null. RandR won't compute the legacy LUT, causing LUT interpolation/composition to spit out an invalid LUT. I verified this by commenting out the `pScrn->depth == 30` conditionals guarding the legacy gamma features (in pre_init, and mode_major). I'm not certain of the best way to fix this. Would it make sense to enable legacy gamma on 30bpp if non-legacy is supported? We can do that since legacy gamma gets interpolated/composed to non-legacy. However, it doesn't make sense when you look at the LUT size, since legacy gamma supports only 256 elements (should be 1024 on depth 30?) In which case we can skip interpolation/composition altogether. Leo
