CVE-2026-43477

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/i915/vrr: Configure VRR timings after enabling TRANS_DDI_FUNC_CTL<br /> <br /> Apparently ICL may hang with an MCE if we write TRANS_VRR_VMAX/FLIPLINE<br /> before enabling TRANS_DDI_FUNC_CTL.<br /> <br /> Personally I was only able to reproduce a hang (on an Dell XPS 7390<br /> 2-in-1) with an external display connected via a dock using a dodgy<br /> type-C cable that made the link training fail. After the failed<br /> link training the machine would hang. TGL seemed immune to the<br /> problem for whatever reason.<br /> <br /> BSpec does tell us to configure VRR after enabling TRANS_DDI_FUNC_CTL<br /> as well. The DMC firmware also does the VRR restore in two stages:<br /> - first stage seems to be unconditional and includes TRANS_VRR_CTL<br /> and a few other VRR registers, among other things<br /> - second stage is conditional on the DDI being enabled,<br /> and includes TRANS_DDI_FUNC_CTL and TRANS_VRR_VMAX/VMIN/FLIPLINE,<br /> among other things<br /> <br /> So let&amp;#39;s reorder the steps to match to avoid the hang, and<br /> toss in an extra WARN to make sure we don&amp;#39;t screw this up later.<br /> <br /> BSpec: 22243<br /> (cherry picked from commit 93f3a267c3dd4d811b224bb9e179a10d81456a74)