[PATCH 0/1] drm/hisilicon/hibmc: Make CONFIG_DRM_HISI_HIBMC depend on ARM64

[Matthew Ruffell]

Hi,

amd64 based Huawei servers have problems where the display output of their iBMC 
chips is broken, resulting in a "blurry" screen when viewed from their in house 
remote kvm-like console.

Example:

https://launchpadlibrarian.net/365907668/creen_picture_for_blur.png

The issue is caused by the hibmc_drm kernel module being loaded. The PCI ID for 
the iBMC chips on amd64 hardware is the same as arm64 hardware, but the
hibmc_drm driver was developed only for use on arm64 hardware, most notably for 
the Huawei D05 development board.

The impact to Huawei is that their customers cannot use Ubuntu server install
media as the screen goes "blurry" when the d-i install media or subuqity
installer loads the hibmc_drm kernel module after language selection.

The only workaround for their customers is to press the "E" key during the very 
first installer menu and adding "modprobe.blacklist=hibmc_drm" to the kernel 
command line in the grub menu. This is not good for customer experience with 
their servers.

Huawei help site on the matter:

https://support.huawei.com/enterprise/en/knowledge/EKB1100015521

Other problems exist for the hibmc_drm driver on amd64, such as working on
bios, but not uefi, and not being wayland compatible, making the screen "blurry" 
whenever a desktop session is started and gdm loaded.

More information about the above can be found on Launchpad:

https://bugs.launchpad.net/bugs/1762940

Huawei have asked us to remove hibmc_drm from all architectures except arm64,
and this aligns with advice from Hisilicon.

Hibmc maintainers, can you please review the status of hibmc_drm on amd64 and
confirm that these issues exist, and consider merging the patch to update
Kconfig to set CONFIG_DRM_HISI_HIBMC arm64 only.

Matthew Ruffell (1):
  drm/hisilicon/hibmc: Make CONFIG_DRM_HISI_HIBMC depend on ARM64

 drivers/gpu/drm/hisilicon/hibmc/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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2.20.1