[Intel-gfx] [PATCH 1/2] drm/i915: Do not rely on wm preservation for ILK watermarks
Matt Roper
matthew.d.roper at intel.com
Tue Oct 24 23:01:02 UTC 2017
On Thu, Oct 19, 2017 at 05:13:40PM +0200, Maarten Lankhorst wrote:
> The original intent was to preserve watermarks as much as possible
> in intel_pipe_wm.raw_wm, and put the validated ones in intel_pipe_wm.wm.
>
> It seems this approach is insufficient and we don't always preserve
> the raw watermarks, so just use the atomic iterator we're already using
> to get a const pointer to all bound planes on the crtc.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102373
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: stable at vger.kernel.org #v4.8+
It's been a while since I looked at this code, so I'm not sure I'm
following all the context/history here. Before this patch, we had
calculated watermarks for all levels (even those above the maximum
usable watermark level as determined by sprite usage) into raw_wm. But
as far as I can tell, we never actually used those values for anything
so that was no different than just throwing the values away?
Is my understanding correct that this is mostly a revert of 71f0a62614
("drm/i915: Only use sanitized values for ILK watermarks) except that it
also modifies the level validation loop so that we're only calling
ilk_compute_wm_level() on the levels up to usable_level whereas before
that patch we were calling it on all levels, but then
setting wm->enable = false for the unusable levels?
By my understanding, this looks like a safe simplification of the
current logic, but I don't see where the functional change is here.
Was the Buzilla: reference supposed to be tied to patch #2 of this
series or am I missing something important?
Matt
> ---
> drivers/gpu/drm/i915/intel_drv.h | 1 -
> drivers/gpu/drm/i915/intel_pm.c | 51 +++++++++++++++++-----------------------
> 2 files changed, 21 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 47d022d48718..7bc60c848940 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -499,7 +499,6 @@ struct intel_crtc_scaler_state {
>
> struct intel_pipe_wm {
> struct intel_wm_level wm[5];
> - struct intel_wm_level raw_wm[5];
> uint32_t linetime;
> bool fbc_wm_enabled;
> bool pipe_enabled;
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index c42a65a93b3a..ea70c720f492 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -2721,9 +2721,9 @@ static void ilk_compute_wm_level(const struct drm_i915_private *dev_priv,
> const struct intel_crtc *intel_crtc,
> int level,
> struct intel_crtc_state *cstate,
> - struct intel_plane_state *pristate,
> - struct intel_plane_state *sprstate,
> - struct intel_plane_state *curstate,
> + const struct intel_plane_state *pristate,
> + const struct intel_plane_state *sprstate,
> + const struct intel_plane_state *curstate,
> struct intel_wm_level *result)
> {
> uint16_t pri_latency = dev_priv->wm.pri_latency[level];
> @@ -3043,28 +3043,24 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> struct intel_pipe_wm *pipe_wm;
> struct drm_device *dev = state->dev;
> const struct drm_i915_private *dev_priv = to_i915(dev);
> - struct intel_plane *intel_plane;
> - struct intel_plane_state *pristate = NULL;
> - struct intel_plane_state *sprstate = NULL;
> - struct intel_plane_state *curstate = NULL;
> + struct drm_plane *plane;
> + const struct drm_plane_state *plane_state;
> + const struct intel_plane_state *pristate = NULL;
> + const struct intel_plane_state *sprstate = NULL;
> + const struct intel_plane_state *curstate = NULL;
> int level, max_level = ilk_wm_max_level(dev_priv), usable_level;
> struct ilk_wm_maximums max;
>
> pipe_wm = &cstate->wm.ilk.optimal;
>
> - for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
> - struct intel_plane_state *ps;
> -
> - ps = intel_atomic_get_existing_plane_state(state,
> - intel_plane);
> - if (!ps)
> - continue;
> + drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, &cstate->base) {
> + const struct intel_plane_state *ps = to_intel_plane_state(plane_state);
>
> - if (intel_plane->base.type == DRM_PLANE_TYPE_PRIMARY)
> + if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> pristate = ps;
> - else if (intel_plane->base.type == DRM_PLANE_TYPE_OVERLAY)
> + else if (plane->type == DRM_PLANE_TYPE_OVERLAY)
> sprstate = ps;
> - else if (intel_plane->base.type == DRM_PLANE_TYPE_CURSOR)
> + else if (plane->type == DRM_PLANE_TYPE_CURSOR)
> curstate = ps;
> }
>
> @@ -3086,11 +3082,9 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> if (pipe_wm->sprites_scaled)
> usable_level = 0;
>
> - ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> - pristate, sprstate, curstate, &pipe_wm->raw_wm[0]);
> -
> memset(&pipe_wm->wm, 0, sizeof(pipe_wm->wm));
> - pipe_wm->wm[0] = pipe_wm->raw_wm[0];
> + ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> + pristate, sprstate, curstate, &pipe_wm->wm[0]);
>
> if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
> pipe_wm->linetime = hsw_compute_linetime_wm(cstate);
> @@ -3100,8 +3094,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
>
> ilk_compute_wm_reg_maximums(dev_priv, 1, &max);
>
> - for (level = 1; level <= max_level; level++) {
> - struct intel_wm_level *wm = &pipe_wm->raw_wm[level];
> + for (level = 1; level <= usable_level; level++) {
> + struct intel_wm_level *wm = &pipe_wm->wm[level];
>
> ilk_compute_wm_level(dev_priv, intel_crtc, level, cstate,
> pristate, sprstate, curstate, wm);
> @@ -3111,13 +3105,10 @@ static int ilk_compute_pipe_wm(struct intel_crtc_state *cstate)
> * register maximums since such watermarks are
> * always invalid.
> */
> - if (level > usable_level)
> - continue;
> -
> - if (ilk_validate_wm_level(level, &max, wm))
> - pipe_wm->wm[level] = *wm;
> - else
> - usable_level = level;
> + if (!ilk_validate_wm_level(level, &max, wm)) {
> + memset(wm, 0, sizeof(*wm));
> + break;
> + }
> }
>
> return 0;
> --
> 2.14.1
>
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--
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795
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