<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - [ivb] Unable to configure 3rd pipe (e.g. LVDS + DP + DP)" href="https://bugs.freedesktop.org/show_bug.cgi?id=89661#c25">Comment # 25</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - [ivb] Unable to configure 3rd pipe (e.g. LVDS + DP + DP)" href="https://bugs.freedesktop.org/show_bug.cgi?id=89661">bug 89661</a> from <a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> Ville Syrjala</a> <pre>The problem is that we may end up using 1.62 link rate for one DP port, and 2.7 for the other DP port, leaving no free DPLLs for the non-DP port. Fixing this requires that we'd consider the failure to find a DPLL as a reason to retry in the bw_constrained mode (or some similar mode) and made the DP link rate selection try to pick a common rate for all ports. I have a branch [1] that cleans up some of the retry logic to better deal with FDI bifurcation (another common reason for failed 3 pipe configuration on IVB), but it doesn't deal with this DPLL issue. IIRC one problem is that we do the DPLL computation way too late to retry easily. I think we'd have to move it a bit, which would also allow us to use the accurate clock in various check functions. And then we'd need to adjust the DP compute_config logic to pick a common rate somehow (just go for the max?). Anyways, I think my bifurcation branch might be a decent first step in making the retry logic nicer. [1] git://github.com/vsyrjala/linux.git ivb_bifurcation_atomic_7</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> <li>You are the assignee for the bug.</li> </ul> </body> </html>