[Intel-gfx] [PATCH v3] tests/gem_reg_read: Extend and check for valid 36b counter

[Chris Wilson]

On Thu, Jul 16, 2015 at 01:19:09PM +0200, Michał Winiarski wrote:
> When reading the timestamp register with single 64b read, we are observing
> invalid values on x86_64:
> 
>     [f = valid counter value | X = garbage]
> 
>     i386:   0x0000000fffffffff
>     x86_64: 0xffffffffXXXXXXXX
> 
> Test checks if the counter is moving and increasing.
> Add a check to see if we can use (reg | 1) flag to get a proper 36b timestamp,
> shifting the value on x86_64 if we can't.
> 
> v2: More iterations of monotonic test, comments, minor fixups (Chris)
> v3: Skip tests if reg_read is not supported
> 
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>

Lgtm,
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre