<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - [HD4600] DVI does not support dual-link" href="https://bugs.freedesktop.org/show_bug.cgi?id=75345#c8">Comment # 8</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - [HD4600] DVI does not support dual-link" href="https://bugs.freedesktop.org/show_bug.cgi?id=75345">bug 75345</a> from <a class="email" href="mailto:a.nielsen@shikadi.net" title="Adam Nielsen <a.nielsen@shikadi.net>"> Adam Nielsen</a> <pre>Looks like you're right - I checked the specs, and a few weeks after I bought the board the spec was updated to say the max DVI res was 1920x1200@60Hz. I wish they'd just supplied a couple of DP ports and a DVI adapter instead... (In reply to <a href="show_bug.cgi?id=75345#c4">comment #4</a>) > (Instead of adopting dual-link, Intel developed a higher bandwidth > connector, DisplayPort - unfortunately the world has been slow jumping on > the bandwagon.) Ironically of my four screens, two of them support DisplayPort but I can't connect them both via DP because the Intel motherboard doesn't provide enough DP connectors! (In reply to <a href="show_bug.cgi?id=75345#c5">comment #5</a>) > IIUC dual-link DVI does not work with the Windows driver either (but I have > no confirmation). I'm a bit on thin ice here, but I don't think increasing > the HDMI frequency directly helps dual-link DVI unless there's some active > components supporting dual-link. It depends on how the DVI port is set up I > guess. I guess this might affect the maximum resolution possible over single-link DVI, but I believe this monitor will only sync with 1920x1200@60Hz over single-link, so any bandwidth increases over the single link won't work. I believe this because there's a HDMI input but it only supports up to 1920x1200@60Hz. I also tried a modeline for 2560x1600@30Hz (native res, and refresh rate that just fits within single-link's bandwidth) but the monitor came up saying the vertical refresh was out of range. > Adam, are you running at least kernel v3.11? I'm running kernel 3.13.4, and last tested the dual-link under 3.12. (In reply to <a href="show_bug.cgi?id=75345#c6">comment #6</a>) > The other thing to remember is that the monitor will not advertise a > dual-link mode to -intel (because it using the wrong connector). Therefore I > feel reasonably confident that if it is in the EDID then we are pruning it, > which should then be fixable by bumping our clock limits to the hw maximum. At least under kernel 3.12 with the DVI-D dual-link cable, it was showing 2560x1600@60Hz as a valid mode and KMS was selecting it by default, resulting in no picture shortly after boot. I think the monitor is advertising all modes and expecting the driver to prune it if dual-link is unavailable. In summary, it looks like Chris is right and the hardware is not dual-link capable. So I guess the bug is that the driver attempts to set a dual-link mode when it is not achievable. I should add the DVI output is reported by KMS as a HDMI output, so perhaps it's not possible to identify it as a DVI port and limit the bandwidth? If this is correct, then in theory one should be able to connect a HDMI 1.4 capable monitor (not mine) to the DVI port with a passive adapter, and get 2560x1600@60Hz.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>