Re: [RESEND PATCH v14 2/2] drm/i915: Put "cooked" vlank counters in frame CRC lines

From: Ville Syrjälä
Date: Tue Jan 10 2017 - 10:55:07 EST


On Tue, Jan 10, 2017 at 02:43:05PM +0100, Tomeu Vizoso wrote:
> Use drm_accurate_vblank_count so we have the full 32 bit to represent
> the frame counter and userspace has a simpler way of knowing when the
> counter wraps around.
>
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
> Reviewed-by: Emil Velikov <emil.velikov@xxxxxxxxxxxxx>
> Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxxxxx>
> ---
>
> drivers/gpu/drm/i915/i915_irq.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index b9beb5955dae..75fb1f66cc0c 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1557,7 +1557,6 @@ static void display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
> struct drm_driver *driver = dev_priv->drm.driver;
> uint32_t crcs[5];
> int head, tail;
> - u32 frame;
>
> spin_lock(&pipe_crc->lock);
> if (pipe_crc->source) {
> @@ -1612,8 +1611,9 @@ static void display_pipe_crc_irq_handler(struct drm_i915_private *dev_priv,
> crcs[2] = crc2;
> crcs[3] = crc3;
> crcs[4] = crc4;
> - frame = driver->get_vblank_counter(&dev_priv->drm, pipe);
> - drm_crtc_add_crc_entry(&crtc->base, true, frame, crcs);
> + drm_crtc_add_crc_entry(&crtc->base, true,
> + drm_accurate_vblank_count(&crtc->base),

My assumption would be that this gets called after the vblank irq
handler, so using the _accurate version seems a bit overkill.

> + crcs);
> }
> }
> #else
> --
> 2.9.3

--
Ville Syrjälä
Intel OTC