On Mon, Dec 19, 2016 at 05:38:57PM +0530, Archit Taneja wrote:
> This code has been more or less picked up from the vc4 and intel
> implementations of update_plane() funcs for cursor planes.
>
> The update_plane() func is usually the drm_atomic_helper_update_plane
> func that will issue an atomic commit with the plane updates. Such
> commits are not intended to be done faster than the vsync rate.
>
> The legacy cursor userspace API, on the other hand, expects the kernel
> to handle cursor updates immediately.
>
> Create a fast path in update_plane, which updates the cursor registers
> and flushes the configuration. The fast path is taken when there is only
> a change in the cursor's position in the crtc, or a change in the
> cursor's crop co-ordinates. For anything else, we go via the slow path.
>
> We take the slow path even whenever the fb changes, and even when there
> is currently no fb tied to the plane. This should hopefully ensure that
> we always take a slow path for every new fb. The slow path will ensure
> that the fb is prepared/pinned etc.
>
> Cc:
> Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
I wonder whether it's time to extract this pattern into some helpers. I
think a combo of async_check and async_flip callbacks on planes should do
the trick and integrate somewhat into atomic overall. amdgpu also needs
this for async flips on the primary plane.
Both async_check and async_flip would take only (struct drm_plane *plane,
struct drm_plane_state *state) as arguments. Maybe we should even wrap
that up into an struct drm_async_flip so that we can add more stuff in the
future.
But all still a bit unclear to me.
> ---
> - Don't know what to do for locking here :/
>
> drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c | 7 ++
> drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 1 +
> drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c | 109 +++++++++++++++++++++++++++++-
> 3 files changed, 114 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
> index 84fcb6e..d0c8b38 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
> @@ -778,6 +778,13 @@ void mdp5_crtc_set_pipeline(struct drm_crtc *crtc,
> mdp5_ctl_set_pipeline(ctl, intf, lm);
> }
>
> +struct mdp5_ctl *mdp5_crtc_get_ctl(struct drm_crtc *crtc)
> +{
> + struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
> +
> + return mdp5_crtc->ctl;
> +}
> +
> int mdp5_crtc_get_lm(struct drm_crtc *crtc)
> {
> struct mdp5_crtc *mdp5_crtc = to_mdp5_crtc(crtc);
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> index 5be50c7..d3b728b 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> @@ -250,6 +250,7 @@ void mdp5_plane_complete_commit(struct drm_plane *plane,
> struct drm_plane *mdp5_plane_init(struct drm_device *dev,
> enum drm_plane_type type);
>
> +struct mdp5_ctl *mdp5_crtc_get_ctl(struct drm_crtc *crtc);
> uint32_t mdp5_crtc_vblank(struct drm_crtc *crtc);
>
> int mdp5_crtc_get_lm(struct drm_crtc *crtc);
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> index 107bb3a..728dad7 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c
> @@ -31,6 +31,14 @@ static int mdp5_plane_mode_set(struct drm_plane *plane,
> struct drm_crtc *crtc, struct drm_framebuffer *fb,
> struct drm_rect *src, struct drm_rect *dest);
>
> +static int mdp5_update_cursor_plane_legacy(struct drm_plane *plane,
> + struct drm_crtc *crtc,
> + struct drm_framebuffer *fb,
> + int crtc_x, int crtc_y,
> + unsigned int crtc_w, unsigned int crtc_h,
> + uint32_t src_x, uint32_t src_y,
> + uint32_t src_w, uint32_t src_h);
> +
> static void set_scanout_locked(struct drm_plane *plane,
> struct drm_framebuffer *fb);
>
> @@ -246,6 +254,19 @@ static void mdp5_plane_destroy_state(struct drm_plane *plane,
> .atomic_print_state = mdp5_plane_atomic_print_state,
> };
>
> +static const struct drm_plane_funcs mdp5_cursor_plane_funcs = {
> + .update_plane = mdp5_update_cursor_plane_legacy,
> + .disable_plane = drm_atomic_helper_disable_plane,
> + .destroy = mdp5_plane_destroy,
> + .set_property = drm_atomic_helper_plane_set_property,
> + .atomic_set_property = mdp5_plane_atomic_set_property,
> + .atomic_get_property = mdp5_plane_atomic_get_property,
> + .reset = mdp5_plane_reset,
> + .atomic_duplicate_state = mdp5_plane_duplicate_state,
> + .atomic_destroy_state = mdp5_plane_destroy_state,
> + .atomic_print_state = mdp5_plane_atomic_print_state,
> +};
> +
> static int mdp5_plane_prepare_fb(struct drm_plane *plane,
> struct drm_plane_state *new_state)
> {
> @@ -873,6 +894,81 @@ static int mdp5_plane_mode_set(struct drm_plane *plane,
> return ret;
> }
>
> +static int mdp5_update_cursor_plane_legacy(struct drm_plane *plane,
> + struct drm_crtc *crtc, struct drm_framebuffer *fb,
> + int crtc_x, int crtc_y,
> + unsigned int crtc_w, unsigned int crtc_h,
> + uint32_t src_x, uint32_t src_y,
> + uint32_t src_w, uint32_t src_h)
> +{
> + struct drm_plane_state *plane_state, *new_plane_state;
> + struct mdp5_plane_state *mdp5_pstate;
> + struct drm_crtc_state *crtc_state = crtc->state;
> + int ret;
> +
> + if (!crtc_state->active || drm_atomic_crtc_needs_modeset(crtc_state))
Until you do some kind of normal flip on the primary after a modeset no
one will ever change the needs_modeset(crtc_state) if you only ever do
async flips. Sounds like a bug, and vc4 doesn't check for it. Why do you
need this?
> + goto slow;
> +
> + plane_state = plane->state;
> + mdp5_pstate = to_mdp5_plane_state(plane_state);
> +
> + /* don't use fast path if we don't have a hwpipe allocated yet */
> + if (!mdp5_pstate->hwpipe)
> + goto slow;
> +
> + /* only allow changing of position(crtc x/y or src x/y) in fast path */
> + if (plane_state->crtc != crtc ||
> + plane_state->src_w != src_w ||
> + plane_state->src_h != src_h ||
> + plane_state->crtc_w != crtc_w ||
> + plane_state->crtc_h != crtc_h ||
> + !plane_state->fb ||
> + plane_state->fb != fb)
> + goto slow;
> +
> + new_plane_state = mdp5_plane_duplicate_state(plane);
> + if (!new_plane_state)
> + return -ENOMEM;
> +
> + new_plane_state->src_x = src_x;
> + new_plane_state->src_y = src_y;
> + new_plane_state->src_w = src_w;
> + new_plane_state->src_h = src_h;
> + new_plane_state->crtc_x = crtc_x;
> + new_plane_state->crtc_y = crtc_y;
> + new_plane_state->crtc_w = crtc_w;
> + new_plane_state->crtc_h = crtc_h;
> +
> + ret = mdp5_plane_atomic_check_with_state(crtc_state, new_plane_state);
> + if (ret)
> + goto slow_free;
> +
> + if (new_plane_state->visible) {
> + struct mdp5_ctl *ctl;
> +
> + ret = mdp5_plane_mode_set(plane, crtc, fb,
> + &new_plane_state->src,
> + &new_plane_state->dst);
> + WARN_ON(ret < 0);
> +
> + ctl = mdp5_crtc_get_ctl(crtc);
> +
> + mdp5_ctl_commit(ctl, mdp5_plane_get_flush(plane));
> + }
> +
> + *to_mdp5_plane_state(plane_state) = *to_mdp5_plane_state(new_plane_state);
> +
> + mdp5_plane_destroy_state(plane, new_plane_state);
Even if the don't go the full monty, at least a
drm_legacy_cursor_helper_update_plane which encodes the above would be
good. I think it should be possible to code it up using the ->atomic_check
and ->atomic_update callbacks ...
But just ideas really, might be better to wait for yet another driver to
explore this space before we consolidate ;-)
-Daniel
> +
> + return 0;
> +slow_free:
> + mdp5_plane_destroy_state(plane, new_plane_state);
> +slow:
> + return drm_atomic_helper_update_plane(plane, crtc, fb,
> + crtc_x, crtc_y, crtc_w, crtc_h,
> + src_x, src_y, src_w, src_h);
> +}
> +
> enum mdp5_pipe mdp5_plane_pipe(struct drm_plane *plane)
> {
> struct mdp5_plane_state *pstate = to_mdp5_plane_state(plane->state);
> @@ -920,9 +1016,16 @@ struct drm_plane *mdp5_plane_init(struct drm_device *dev, enum drm_plane_type ty
> mdp5_plane->nformats = mdp_get_formats(mdp5_plane->formats,
> ARRAY_SIZE(mdp5_plane->formats), false);
>
> - ret = drm_universal_plane_init(dev, plane, 0xff, &mdp5_plane_funcs,
> - mdp5_plane->formats, mdp5_plane->nformats,
> - type, NULL);
> + if (type == DRM_PLANE_TYPE_CURSOR)
> + ret = drm_universal_plane_init(dev, plane, 0xff,
> + &mdp5_cursor_plane_funcs,
> + mdp5_plane->formats, mdp5_plane->nformats,
> + type, NULL);
> + else
> + ret = drm_universal_plane_init(dev, plane, 0xff,
> + &mdp5_plane_funcs,
> + mdp5_plane->formats, mdp5_plane->nformats,
> + type, NULL);
> if (ret)
> goto fail;
>
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> hosted by The Linux Foundation
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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