How to fix Linux CMA on x86 with internal graphic card i915/hda_intel ioremap error?

From: Suesens, Sebastian
Date: Mon Mar 25 2024 - 15:14:17 EST


Hello,
I enabled the CMA (CONFIG_CMA=y) for an x86 machine on Linux kernel v5.10 and v5.15 When I boot the system the CMA reserved memory, but when the graphic card driver i915 or hda_intel is loaded the system crashed.
I see that ioremap on RAM at 0x0000000000000000 - 0x00000000d0000000 get fail. When I blacklist the i915 and hda_intel module the system boots fine with cma memory reserved.

I think this has something to do with the shared memory which this driver use.

Does anyone know if a kernel config or something else prevents this crash?

Please answer me in CC.

Regards Sebastian