<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [LPT SPT KBP] Acer V3-772G screen brightness cannot be adjusted with i915.fastboot enabled" href="https://bugs.freedesktop.org/show_bug.cgi?id=108225#c28">Comment # 28</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [LPT SPT KBP] Acer V3-772G screen brightness cannot be adjusted with i915.fastboot enabled" href="https://bugs.freedesktop.org/show_bug.cgi?id=108225">bug 108225</a> from <a class="email" href="mailto:cevelnet@gmail.com" title="Tolga Cakir <cevelnet@gmail.com>"> Tolga Cakir</a> <pre>(In reply to Maarten Lankhorst from <a href="show_bug.cgi?id=108225#c25">comment #25</a>) > Created <a href="attachment.cgi?id=142472" name="attach_142472" title="(hopefully) Flicker free version of switching backlight method.">attachment 142472</a> <a href="attachment.cgi?id=142472&action=edit" title="(hopefully) Flicker free version of switching backlight method.">[details]</a> <a href='page.cgi?id=splinter.html&bug=108225&attachment=142472'>[review]</a> [review] > (hopefully) Flicker free version of switching backlight method. > > Can you test if this works? If not the previous patch should work. I have tested the patch in <a href="show_bug.cgi?id=108225#c25">comment #25</a> on Arch Linux and patched against drm-intel-next branch. My observations: when I power on my laptop, the default brightness is set around 50% brightness. When i915 gets loaded, the brightness level changes to my user value (saved during shutdown, restored on next boot). The brightness level changes without any form of smoothing, but there is no flickering. It changes strict from e.g. 50% to 75%, without the backlight turning off. After the boot process, backlight controls fully work! However, the flickering is not 100% gone, eventhough it's much better than without fastboot=1. There is a very short screen content blanking, but the backlight stays on. The contents of the screen blank for around ~1/10th of a second and resume where they stopped. Eventhough I still notice a very brief screen flickering, the result is superior to fastboot=0. I'm testing <a href="show_bug.cgi?id=108225#c24">comment #24</a> next and will report back.</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>