[Intel-gfx] [PATCH v4] drm/i915/mocs: Program MOCS for all engines on init

[Peter Antoine]

Chris,

Testcases are underway, validation are working on them.

Peter.

On Tue, 15 Mar 2016, Chris Wilson wrote:

> On Mon, Mar 14, 2016 at 03:11:02PM +0000, Peter Antoine wrote:
>> Allow for the MOCS to be programmed for all engines.
>> Currently we program the MOCS when the first render batch
>> goes through. This works on most platforms but fails on
>> platforms that do not run a render batch early,
>> i.e. headless servers. The patch now programs all initialised engines
>> on init and the RCS is programmed again within the initial batch. This
>> is done for predictable consistency with regards to the hardware
>> context.
>>
>> Hardware context loading sets the values of the MOCS for RCS
>> and L3CC. Programming them from within the batch makes sure that
>> the render context is valid, no matter what the previous state of
>> the saved-context was.
>>
>> v2: posted correct version to the mailing list.
>> v3: moved programming to within engine->init_hw() (Chris Wilson)
>> v4: code formatting and white-space changes. (Chris Wilson)
>>
>> Signed-off-by: Peter Antoine <peter.antoine at intel.com>
>
> So testcase?
>
> Execute a bunch of MI_STORE_REGISTER_MEM on the various rings in a fresh
> context each time and confirm the ABI for the first N locations.
>
> Repeat across suspend/resume (i.e. make sure the context image maintain
> the register state). Then verify that freshly constructed contexts also
> have the correct settings after resume.
> -Chris
>
>

--
    Peter Antoine (Android Graphics Driver Software Engineer)
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