[PATCH][Zesty][SRU 0/1] Fix for LP#1698700

[Daniel Axtens]

BugLink: https://bugs.launchpad.net/bugs/1698700

[Impact]
On the HiSilicon D05 (arm64) board, X crashes when started. [0]

[Fix]
The crash is attributable to the bus ID that the hibmc driver
reports for the hibmc graphics card on the board. In particular, the
bus id is missing the "pci:" prefix that most other cards provide: [1]

- The busid reported on the arm64 system is "0007:a1:00.0"
- The busid reported on a amd64 system is "pci:0000:00:02.0"

X tests for this prefix. A missing prefix for PCI cards leads to an Xorg crash.

Fix this by using the set_pci_busid function from the DRM core.

[Testcase]
Successfully tested on a D05 board. [2]

[Regression Potential]
Changes are limited to the hibmc driver, so any regression should also
be limited to that driver.

[Notes]
I submitted the patch upstream. However, upstream is refactoring the
drm core, and set_busid is going away. That does fix this issue but
the regression potential of the refactor is enormous, so this seems
like the wiser approach. [3]

[0]: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1691991
[1]: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1691991/comments/16
[2]: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1691991/comments/29
[3]: https://www.spinics.net/lists/dri-devel/msg143831.html

Daniel Axtens (1):
  UBUNTU: SAUCE: drm: hibmc: Use set_busid function from drm core

 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 1 +
 1 file changed, 1 insertion(+)

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2.11.0