Re: [PATCH 55/62] drm/i915/bdw: Disable semaphores

Jesse Barnes
2013-11-04T18:18:01Z

On Sat, 2 Nov 2013 21:07:53 -0700
Ben Widawsky <benjamin.widawsky@intel.com> wrote:

> From: Ben Widawsky <ben@bwidawsk.net>
>
> We've done insufficient testing on them thus far, so keep them disabled
> until we do test.
>
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 590d999..efb63b0 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -478,6 +478,12 @@ bool i915_semaphore_is_enabled(struct drm_device *dev)
> if (INTEL_INFO(dev)->gen < 6)
> return 0;
>
> + /* Until we get further testing... */
> + if (IS_GEN8(dev)) {
> + DRM_INFO("Semaphores disabled GEN8\n");
> + return 0;
> + }
> +
> if (i915_semaphores >= 0)
> return i915_semaphores;
>

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Side note; for stuff like this where we disable a critical feature
(e.g. PPGTT, semaphores) with the intention of enabling it later, maybe
we should do a WARN or something if preliminary hw support is enabled.
Or somehow catch it so we have to address it before declaring the bits
good.

--
Jesse Barnes, Intel Open Source Technology Center