ACK: [B][PATCH 0/1] Fix LP: #1738334 - hisilicon hibmc regression

[Colin Ian King]

On 01/03/18 10:01, Daniel Axtens wrote:
> From: Daniel Axtens <dja at axtens.net>
> 
> [SRU Justification]
> 
> [Impact]
> On Artful and Bionic kernels, X fails to start and a kernel splat is printed.
> 
> This is because ea642c3216cb ("drm/ttm: add io_mem_pfn callback") is
> incomplete: the hisilicon hibmc driver does not contain the callback
> and so the kernel tries to execute code at NULL.
> 
> [Fix]
> 
> Bionic: There is a generic fix in 4.16 at
> c67fa6edc8b11afe22c88a23963170bf5f151acf. It is part of a series that
> applies this generic fix and does a bunch of cleanups; we can safely
> just pick up the generic fix.
> 
> Artful: Rather than a generic fix, I have submitted a very very
> minimal fix that only touches hibmc. [This has since been applied and
> released.]
> 
> [Regression Potential]
> 
> Artful: Minimal - fix only touches hibmc driver. Tested on D05 board.
> 
> Bionic: fix is to generic drm code, but is small and easily reviewable.
> 
> [Testcase]
> Install patched kernel, try to start X. If it succeeds, the fix
> works. If there's a kernel splat, the fix does not work.
> 
> Tan Xiaojun (1):
>   drm/ttm: add ttm_bo_io_mem_pfn to check io_mem_pfn
> 
>  drivers/gpu/drm/ttm/ttm_bo_vm.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
Positive test results, clean cherry pick.

Acked-by: Colin Ian King <colin.king at canonical.com>