<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [GM45 backlight] LCD waterfall effect on HP 2230s laptop" href="https://bugs.freedesktop.org/show_bug.cgi?id=72289#c42">Comment # 42</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [GM45 backlight] LCD waterfall effect on HP 2230s laptop" href="https://bugs.freedesktop.org/show_bug.cgi?id=72289">bug 72289</a> from <a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> Jani Nikula</a> <pre>(In reply to Jesse Barnes from <a href="show_bug.cgi?id=72289#c41">comment #41</a>) > Well, it's definitely possible we have to re-program the PWM params as those > are panel specific; I think the VBT is supposed to be updated with the > correct values. > > Jani, do we trust those these days? Maybe current bits will behave better? No, we don't look at the PWM freq in VBT, we just use whatever the BIOS used at boot. Which *should* be the same thing. I had patches eons ago to use the VBT freq, but I haven't updated them in a while. The VBT has the frequency in Hz (which I think is a surprisingly sane choice) but translating that to the register value depends on clocks and needs a bunch of platform specific code. And I'm not really sure it's worthwhile to be adding that for the oldest gens.</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> <li>You are the assignee for the bug.</li> </ul> </body> </html>