[Intel-gfx] [PATCH 1/2] drm/i915: Enable mmio_debug for vlv/chv

Mika Kuoppala mika.kuoppala at linux.intel.com
Mon Jan 11 08:53:10 PST 2016

Chris Wilson <chris at chris-wilson.co.uk> writes:

> On Fri, Jan 08, 2016 at 03:51:19PM +0200, Mika Kuoppala wrote:
>> With commit 8ac3e1bb76cc ("drm/i915: Add non claimed mmio checking
>> for vlv/chv") we now have chv/vlv support in place for detecting
>> unclaimed access. Also the perf hit of extra mmio read
>> is now only suffered if mmio_debug is set.
>> This allows us to stuff the macro for unclaimed reg
>> detection inside a generic gen6 register access, as now all
>> gens using these macros uses also unclaimed debugs, the one
>> exception being snb. We gain more clean and generic macros
>> and only downside is that snb will suffer one branch perf hit
>> without upside.
>> Note that the hsw write path debug register check now
>> happens before fifo check, but this should not make
>> any real difference.
>> As vlv/chv use the generic gen6 access macros, the consequence
>> is that they gain the mmio_debug feature.
>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
> I still fancy a GEN6_DBG_READ/WRITE_HEADER but with only a couple of
> gen, it doesn't seem worth the argument. (Though we still need to reduce
> the expense of ilk_irq_handler, but for the most part that is to avoid
> these vfunc altogether.)
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> -Chris

Both patches pushed to dinq. Thankyou for review.


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