Re: [PATCH v2] drm/rockchip: update cursors asynchronously through atomic.

From: Tomasz Figa
Date: Wed Nov 14 2018 - 03:49:51 EST


Hi Enric,

On Fri, Sep 28, 2018 at 5:27 PM Enric Balletbo i Serra
<enric.balletbo@xxxxxxxxxxxxx> wrote:
>
> Add support to async updates of cursors by using the new atomic
> interface for that.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> ---
> Hi,
>
> This is a second version of the patch to add async-plane update support
> to the Rockchip driver.
>

I'm really sorry for the super late reply. I couldn't get cycles to
look at this earlier. :(

> The patch was tested on a Samsung Chromebook Plus in two ways.
>
> 1. Running all igt kms_cursor_legacy and kms_atomic tests and see that
> there is no regression after the patch.
> Note that before the patch, the following igt tests failed:
> - basic-flip-before-cursor-legacy
> - basic-flip-before-cursor-atomic
> - cursor-vs-flip-legacy
> - cursor-vs-flip-toggle
> - flip-vs-cursor-atomic
> - flip-vs-cursor-crc-atomic
> - flip-vs-cursor-crc-legacy
> - flip-vs-cursor-legacy
> - flip-vs-cursor-crc-atomic
> - flip-vs-cursor-crc-legacy

Are the last 2 tests repeated?

>
> With the patch applied only two tests don't fail (these two are
> expexted to not pass right now):
> - flip-vs-cursor-crc-atomic
> - flip-vs-cursor-crc-legac

Did you mean "don't pass"?

>
> You can check full IGT test report here:
> - Before the patch:
> https://people.collabora.com/~eballetbo/tests/igt/samsung-chromebook-plus/igt-1.23/4.19-rc5/index.html
> - With the patch applied:
> https://people.collabora.com/~eballetbo/tests/igt/samsung-chromebook-plus/igt-1.23/4.19-rc5-async-update/index.html
>
> 2. Running weston using the atomic API.
>
> Best regards,
> Enric
>
> Changes in v2:
> - Change the framebuffer as well to cover jumpy cursor when hovering
> text boxes or hyperlink. (Tomasz)
> - Use the PSR inhibit mechanism when accessing VOP hardware instead of
> PSR flushing (Tomasz)
>
> Changes in v1:
> - Rebased on top of drm-misc
> - In async_check call drm_atomic_helper_check_plane_state to check that
> the desired plane is valid and update various bits of derived state
> (clipped coordinates etc.)
> - In async_check allow to configure new scaling in the fast path.
> - In async_update force to flush all registered PSR encoders.
> - In async_update call atomic_update directly.
> - In async_update call vop_cfg_done needed to set the vop registers and take effect.
>
> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 36 ------------
> drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 37 ++++++++++++
> drivers/gpu/drm/rockchip/rockchip_drm_psr.h | 3 +
> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 62 +++++++++++++++++++++
> 4 files changed, 102 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> index 7b6f7227d476..aec9a997de13 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> @@ -128,24 +128,6 @@ rockchip_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
> return ERR_PTR(ret);
> }
>
> -static void
> -rockchip_drm_psr_inhibit_get_state(struct drm_atomic_state *state)
> -{
> - struct drm_crtc *crtc;
> - struct drm_crtc_state *crtc_state;
> - struct drm_encoder *encoder;
> - u32 encoder_mask = 0;
> - int i;
> -
> - for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
> - encoder_mask |= crtc_state->encoder_mask;
> - encoder_mask |= crtc->state->encoder_mask;
> - }
> -
> - drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
> - rockchip_drm_psr_inhibit_get(encoder);
> -}
> -
> uint32_t rockchip_drm_get_vblank_ns(struct drm_display_mode *mode)
> {
> uint64_t vblank_time = mode->vtotal - mode->vdisplay;
> @@ -156,24 +138,6 @@ uint32_t rockchip_drm_get_vblank_ns(struct drm_display_mode *mode)
> return vblank_time;
> }
>
> -static void
> -rockchip_drm_psr_inhibit_put_state(struct drm_atomic_state *state)
> -{
> - struct drm_crtc *crtc;
> - struct drm_crtc_state *crtc_state;
> - struct drm_encoder *encoder;
> - u32 encoder_mask = 0;
> - int i;
> -
> - for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
> - encoder_mask |= crtc_state->encoder_mask;
> - encoder_mask |= crtc->state->encoder_mask;
> - }
> -
> - drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
> - rockchip_drm_psr_inhibit_put(encoder);
> -}
> -
> static void
> rockchip_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
> {
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> index 79d00d861a31..1635485955d3 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c
> @@ -13,6 +13,7 @@
> */
>
> #include <drm/drmP.h>
> +#include <drm/drm_atomic.h>
> #include <drm/drm_crtc_helper.h>
>
> #include "rockchip_drm_drv.h"
> @@ -109,6 +110,42 @@ int rockchip_drm_psr_inhibit_put(struct drm_encoder *encoder)
> }
> EXPORT_SYMBOL(rockchip_drm_psr_inhibit_put);
>
> +void rockchip_drm_psr_inhibit_get_state(struct drm_atomic_state *state)
> +{
> + struct drm_crtc *crtc;
> + struct drm_crtc_state *crtc_state;
> + struct drm_encoder *encoder;
> + u32 encoder_mask = 0;
> + int i;
> +
> + for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
> + encoder_mask |= crtc_state->encoder_mask;
> + encoder_mask |= crtc->state->encoder_mask;
> + }
> +
> + drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
> + rockchip_drm_psr_inhibit_get(encoder);
> +}
> +EXPORT_SYMBOL(rockchip_drm_psr_inhibit_get_state);
> +
> +void rockchip_drm_psr_inhibit_put_state(struct drm_atomic_state *state)
> +{
> + struct drm_crtc *crtc;
> + struct drm_crtc_state *crtc_state;
> + struct drm_encoder *encoder;
> + u32 encoder_mask = 0;
> + int i;
> +
> + for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
> + encoder_mask |= crtc_state->encoder_mask;
> + encoder_mask |= crtc->state->encoder_mask;
> + }
> +
> + drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
> + rockchip_drm_psr_inhibit_put(encoder);
> +}
> +EXPORT_SYMBOL(rockchip_drm_psr_inhibit_put_state);
> +
> /**
> * rockchip_drm_psr_inhibit_get - acquire PSR inhibit on given encoder
> * @encoder: encoder to obtain the PSR encoder
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.h b/drivers/gpu/drm/rockchip/rockchip_drm_psr.h
> index 860c62494496..25350ba3237b 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.h
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.h
> @@ -20,6 +20,9 @@ void rockchip_drm_psr_flush_all(struct drm_device *dev);
> int rockchip_drm_psr_inhibit_put(struct drm_encoder *encoder);
> int rockchip_drm_psr_inhibit_get(struct drm_encoder *encoder);
>
> +void rockchip_drm_psr_inhibit_get_state(struct drm_atomic_state *state);
> +void rockchip_drm_psr_inhibit_put_state(struct drm_atomic_state *state);
> +
> int rockchip_drm_psr_register(struct drm_encoder *encoder,
> int (*psr_set)(struct drm_encoder *, bool enable));
> void rockchip_drm_psr_unregister(struct drm_encoder *encoder);
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index 6642c2b9bb3c..682ce40166f7 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -819,10 +819,72 @@ static void vop_plane_atomic_update(struct drm_plane *plane,
> spin_unlock(&vop->reg_lock);
> }
>
> +static int vop_plane_atomic_async_check(struct drm_plane *plane,
> + struct drm_plane_state *state)
> +{
> + struct vop_win *vop_win = to_vop_win(plane);
> + const struct vop_win_data *win = vop_win->data;
> + int min_scale = win->phy->scl ? FRAC_16_16(1, 8) :
> + DRM_PLANE_HELPER_NO_SCALING;
> + int max_scale = win->phy->scl ? FRAC_16_16(8, 1) :
> + DRM_PLANE_HELPER_NO_SCALING;
> + struct drm_crtc_state *crtc_state;
> + int ret;
> +
> + if (plane != state->crtc->cursor)
> + return -EINVAL;
> +
> + if (!plane->state)
> + return -EINVAL;
> +
> + if (!plane->state->fb)
> + return -EINVAL;
> +
> + if (state->state)
> + crtc_state = drm_atomic_get_existing_crtc_state(state->state,
> + state->crtc);
> + else /* Special case for asynchronous cursor updates. */
> + crtc_state = plane->crtc->state;
> +
> + ret = drm_atomic_helper_check_plane_state(plane->state,
> + crtc_state,
> + min_scale, max_scale,
> + true, true);
> + return ret;
> +}
> +
> +static void vop_plane_atomic_async_update(struct drm_plane *plane,
> + struct drm_plane_state *new_state)
> +{
> + struct vop *vop = to_vop(plane->state->crtc);
> +
> + plane->state->crtc_x = new_state->crtc_x;
> + plane->state->crtc_y = new_state->crtc_y;
> + plane->state->crtc_h = new_state->crtc_h;
> + plane->state->crtc_w = new_state->crtc_w;
> + plane->state->src_x = new_state->src_x;
> + plane->state->src_y = new_state->src_y;
> + plane->state->src_h = new_state->src_h;
> + plane->state->src_w = new_state->src_w;
> +
> + drm_atomic_set_fb_for_plane(plane->state, new_state->fb);

Isn't this going to drop the old fb reference on the floor without
waiting for the hardware to actually stop scanning out from it?

I believe we need to do something similar to what's already in
vop_crtc_commit_flush(), but not called on this async path
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/gpu/drm/rockchip/rockchip_drm_vop.c?h=next-20181114#n1045

Perhaps it would be an option to call vop_crtc_commit_flush() from here?

Best regards,
Tomasz

> +
> + if (vop->is_enabled) {
> + rockchip_drm_psr_inhibit_get_state(new_state->state);
> + vop_plane_atomic_update(plane, plane->state);
> + spin_lock(&vop->reg_lock);
> + vop_cfg_done(vop);
> + spin_unlock(&vop->reg_lock);
> + rockchip_drm_psr_inhibit_put_state(new_state->state);
> + }
> +}
> +
> static const struct drm_plane_helper_funcs plane_helper_funcs = {
> .atomic_check = vop_plane_atomic_check,
> .atomic_update = vop_plane_atomic_update,
> .atomic_disable = vop_plane_atomic_disable,
> + .atomic_async_check = vop_plane_atomic_async_check,
> + .atomic_async_update = vop_plane_atomic_async_update,
> };
>
> static const struct drm_plane_funcs vop_plane_funcs = {
> --
> 2.19.0
>