[v1] drm/msm: add shutdown support for display platform_driver

[Sai Prakash Ranjan]

Hi Krishna,

On 2020-05-28 14:08, Krishna Manikandan wrote:
> Define shutdown callback for display drm driver,
> so as to disable all the CRTCS when shutdown
> notification is received by the driver.
> 

Would be nice to add some more context for adding this shutdown callback
something like below:

If the hardware is still accessing memory after SMMU translation is 
disabled
as part of smmu shutdown callback,  then the IOVAs(I/O virtual address) 
which
it was using will go on the bus as the physical addresses which will 
result
in unknown crashes (NoC/interconnect errors on QCOM SoCs).

PS: Credits for description: Robin Murphy

Thanks,
Sai

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