Hi Andy, On Thu, 2025-08-14 at 22:38 +0800, Chun-Kuang Hu wrote: > Forward to dri-devel and linux-mediatek. > > Andy Chernyak <andy.chern...@gmail.com> 於 2025年7月2日 週三 下午11:12寫道： > > > > Kernel 6.16 has external video (both hdmi and displayport-over- > > usbc) broken (black screen) on mt8173-based chromebooks (platform > > codename "oak", device codename "hana"). Bisect points finger to > > following commit: > > > > From d6e25b3590a0679bca1a1becc04e3999f1dfd461 > > From: Guillaume Ranquet <granq...@baylibre.com> > > Date: Tue, 15 Apr 2025 12:43:05 +0200 > > Subject: drm/mediatek: hdmi: Use regmap instead of iomem for main > > registers > > In preparation for the addition of a new version of the HDMI IP > > which will need to share its iospace between multiple subdrivers, > > and in preparation for moving out the common bits between the two, > > migrate this driver to fully use regmap. > > > > Reverting d6e25b3590 with "patch -R" on top of 6.16-rc4 fixes this.
thank you for the bug report. By reading and checking this patch changes, I found two modifications that looked incorrect, so I sent a patch to fix them: https://lore.kernel.org/dri-devel/20250818-mt8173-fix-hdmi-issue-v1-1-55aff9b02...@collabora.com/ Since I don't have any mt8173-based board myself, could you test this patch and tell if it does fix the issue (or not)? Looking forward to your reply, Regards, Louis-Alexis
