On Sun, 19 Aug 2012 21:12:38 +0200
Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> This is the first tiny step towards cross-checking the entire modeset
> state machine with WARNs. A crtc can only be enabled when it's
> actually in use, i.e. crtc->active imlies crtc->enabled.
>
> Unfortunately we can't (yet) check this when disabling the crtc,
> because the crtc helpers are a bit slopy with updating state and
> unconditionally update crtc->enabled before changing the hw state.
>
> Fixing that requires quite some more work.
>
> Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/i915/intel_display.c | 4 ++++
> drivers/gpu/drm/i915/intel_drv.h | 10 +++++++++-
> 2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index ca17010..5ab8694 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3215,6 +3215,8 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
> u32 temp;
> bool is_pch_port;
>
> + WARN_ON(!crtc->enabled);
> +
> /* XXX: For compatability with the crtc helper code, call the encoder's
> * enable function unconditionally for now. */
> if (intel_crtc->active)
> @@ -3391,6 +3393,8 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc)
> int pipe = intel_crtc->pipe;
> int plane = intel_crtc->plane;
>
> + WARN_ON(!crtc->enabled);
> +
> /* XXX: For compatability with the crtc helper code, call the encoder's
> * enable function unconditionally for now. */
> if (intel_crtc->active)
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 673e8d4..36991de 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -158,7 +158,15 @@ struct intel_crtc {
> enum plane plane;
> u8 lut_r[256], lut_g[256], lut_b[256];
> int dpms_mode;
> - bool active; /* is the crtc on? independent of the dpms mode */
> + /*
> + * Whether the crtc and the connected output pipeline is active. Implies
> + * that crtc->enabled is set, i.e. the current mode configuration has
> + * some outputs connected to this crtc.
> + *
> + * Atm crtc->enabled is unconditionally updated _before_ the hw state is
> + * changed, hence we can only check this when enabling the crtc.
> + */
> + bool active;
> bool primary_disabled; /* is the crtc obscured by a plane? */
> bool lowfreq_avail;
> struct intel_overlay *overlay;
Looking forward to seeing this cleaned up.
Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
--
Jesse Barnes, Intel Open Source Technology Center
