<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [IGT] kms_flip@basic-flip-vs-wf_blank vblank interval differs from modeline" href="https://bugs.freedesktop.org/show_bug.cgi?id=101439#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [IGT] kms_flip@basic-flip-vs-wf_blank vblank interval differs from modeline" href="https://bugs.freedesktop.org/show_bug.cgi?id=101439">bug 101439</a> from <a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> Ville Syrjala</a> <pre>(In reply to Maarten Lankhorst from <a href="show_bug.cgi?id=101439#c1">comment #1</a>) > I've seen this error in <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - [SNB][IVB][BAT] kms_cursor_legacy@basic-busy-flip-before-cursor-atomic fails in CI" href="show_bug.cgi?id=100215">bug 100215</a> too. It appears to be that with 36 bpp > the fake dongle gets a clock speed slightly different from the expected > vblank interval, so this is a real bug. I wouldn't go as far as claiming this is a bug. The difference (at least in the snippets in <a href="show_bug.cgi?id=101439#c1">comment #1</a>) is .2%-.3%, which well within the .5% limit that VESA has specified in some standard. There is a real bug in the driver in that it doesn't actually check if the clock we got is close enough or not. But if we had such a check (and it used the .5% as its guideline) then it wouldn't have tripped in this case. The state readout does do a check like that but I think it allows the error to be quite big.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>