<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - [GLK] no signal - with samsung 4k TV - HDMI UHD Color (ENABLED)" href="https://bugs.freedesktop.org/show_bug.cgi?id=110496#c29">Comment # 29</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - [GLK] no signal - with samsung 4k TV - HDMI UHD Color (ENABLED)" href="https://bugs.freedesktop.org/show_bug.cgi?id=110496">bug 110496</a> from <a class="email" href="mailto:sergey79@gmail.com" title="sergey79@gmail.com">sergey79@gmail.com</a> <pre>(In reply to <a href="mailto:shashank.sharma@intel.com">shashank.sharma@intel.com</a> from <a href="show_bug.cgi?id=110496#c27">comment #27</a>) > That's why we can see 4k@30 deep color, 4k@60 YCBCR 420 deep color outputs > working on this TV, but as soon as we switch to RGB 4k@60, the driver > restricts the HDMI output to 4k@60 8BPC, which is being rejected by the TV, > in the UHD mode of operation. 420 works only @50/60Hz, only @ 8-bit. 420 @ deep color and other refresh rates (24/25/30) is not supported by the TV at all (with UHD Color on or off). The only difference between "HDMI UHD Color" on and off is that TV sends different EDID data. I analyzed both EDIDs - basically the only important difference is the presence of HDMI-Forum VSDB block which enable Deep Color in 4k modes. 4k modes that work (UHD Color off): RGB 24/25/30Hz 8-bit 420 50/60Hz 8-bit 4k modes that don't work (UHD Color on): RGB 24/25/30Hz 12-bit RGB 50/60Hz 8-bit As you can see, any mode that require 594 Mhz pixel clock - does not work. And any mode that require only 297 Mhz - works just fine.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>