On Thu, Sep 09, 2021 at 12:49:16PM -0700, José Roberto de Souza wrote:
> By now all the userspace applications should have migrated to atomic
> or at least be calling DRM_IOCTL_MODE_DIRTYFB.
>
> With that we can kill frontbuffer rendering support in i915 for
> modern platforms.
>
> So here converting legacy APIs into atomic commits so it can be
> properly handled by driver i915.
>
> Several IGT tests will fail with this changes, because some tests
> were stressing those frontbuffer rendering scenarios that no userspace
> should be using by now, fixes to IGT should be sent soon.
>
I just gave this a try here and it's unusable. glxgears went from
9000 to 120 fps (was expecting 60fps tbh, not sure why I get
double), everything lags like mad, if I drag a window around
glxgears/other windows stop updating entirely, etc. NAK
> v2:
> - return earlier to not set fb_tracking.busy/flip_bits
> - added a warn on to make sure we are not setting the busy/flip_bits
>
> Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx>
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_cursor.c | 6 ++----
> drivers/gpu/drm/i915/display/intel_fb.c | 8 +++++++-
> .../gpu/drm/i915/display/intel_frontbuffer.c | 18 ++++++++++++++++++
> drivers/gpu/drm/i915/i915_drv.h | 2 ++
> 4 files changed, 29 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
> index c7618fef01439..5aa996c3b7980 100644
> --- a/drivers/gpu/drm/i915/display/intel_cursor.c
> +++ b/drivers/gpu/drm/i915/display/intel_cursor.c
> @@ -617,6 +617,7 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
> u32 src_w, u32 src_h,
> struct drm_modeset_acquire_ctx *ctx)
> {
> + struct drm_i915_private *i915 = to_i915(_crtc->dev);
> struct intel_plane *plane = to_intel_plane(_plane);
> struct intel_crtc *crtc = to_intel_crtc(_crtc);
> struct intel_plane_state *old_plane_state =
> @@ -633,12 +634,9 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
> * PSR2 selective fetch also requires the slow path as
> * PSR2 plane and transcoder registers can only be updated during
> * vblank.
> - *
> - * FIXME bigjoiner fastpath would be good
> */
> if (!crtc_state->hw.active || intel_crtc_needs_modeset(crtc_state) ||
> - crtc_state->update_pipe || crtc_state->bigjoiner ||
> - crtc_state->enable_psr2_sel_fetch)
> + crtc_state->update_pipe || !HAS_FRONTBUFFER_RENDERING(i915))
> goto slow;
>
> /*
> diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
> index e4b8602ec0cd2..3eb60785c9f29 100644
> --- a/drivers/gpu/drm/i915/display/intel_fb.c
> +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> @@ -3,6 +3,7 @@
> * Copyright © 2021 Intel Corporation
> */
>
> +#include <drm/drm_damage_helper.h>
> #include <drm/drm_framebuffer.h>
> #include <drm/drm_modeset_helper.h>
>
> @@ -1235,10 +1236,15 @@ static int intel_user_framebuffer_dirty(struct drm_framebuffer *fb,
> unsigned int num_clips)
> {
> struct drm_i915_gem_object *obj = intel_fb_obj(fb);
> + struct drm_i915_private *i915 = to_i915(obj->base.dev);
>
> i915_gem_object_flush_if_display(obj);
> - intel_frontbuffer_flush(to_intel_frontbuffer(fb), ORIGIN_DIRTYFB);
>
> + if (!HAS_FRONTBUFFER_RENDERING(i915))
> + return drm_atomic_helper_dirtyfb(fb, file, flags, color, clips,
> + num_clips);
> +
> + intel_frontbuffer_flush(to_intel_frontbuffer(fb), ORIGIN_DIRTYFB);
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
> index 0492446cd04ad..3860f87dac31c 100644
> --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c
> +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
> @@ -112,6 +112,9 @@ static void frontbuffer_flush(struct drm_i915_private *i915,
> void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
> unsigned frontbuffer_bits)
> {
> + if (!HAS_FRONTBUFFER_RENDERING(i915))
> + return;
> +
> spin_lock(&i915->fb_tracking.lock);
> i915->fb_tracking.flip_bits |= frontbuffer_bits;
> /* Remove stale busy bits due to the old buffer. */
> @@ -132,6 +135,12 @@ void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
> void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
> unsigned frontbuffer_bits)
> {
> + if (!HAS_FRONTBUFFER_RENDERING(i915)) {
> + drm_WARN_ON_ONCE(&i915->drm, i915->fb_tracking.flip_bits |
> + i915->fb_tracking.busy_bits);
> + return;
> + }
> +
> spin_lock(&i915->fb_tracking.lock);
> /* Mask any cancelled flips. */
> frontbuffer_bits &= i915->fb_tracking.flip_bits;
> @@ -156,6 +165,9 @@ void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
> void intel_frontbuffer_flip(struct drm_i915_private *i915,
> unsigned frontbuffer_bits)
> {
> + if (!HAS_FRONTBUFFER_RENDERING(i915))
> + return;
> +
> spin_lock(&i915->fb_tracking.lock);
> /* Remove stale busy bits due to the old buffer. */
> i915->fb_tracking.busy_bits &= ~frontbuffer_bits;
> @@ -170,6 +182,9 @@ void __intel_fb_invalidate(struct intel_frontbuffer *front,
> {
> struct drm_i915_private *i915 = to_i915(front->obj->base.dev);
>
> + if (!HAS_FRONTBUFFER_RENDERING(i915))
> + return;
> +
> if (origin == ORIGIN_CS) {
> spin_lock(&i915->fb_tracking.lock);
> i915->fb_tracking.busy_bits |= frontbuffer_bits;
> @@ -191,6 +206,9 @@ void __intel_fb_flush(struct intel_frontbuffer *front,
> {
> struct drm_i915_private *i915 = to_i915(front->obj->base.dev);
>
> + if (!HAS_FRONTBUFFER_RENDERING(i915))
> + return;
> +
> if (origin == ORIGIN_CS) {
> spin_lock(&i915->fb_tracking.lock);
> /* Filter out new bits since rendering started. */
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 37c1ca266bcdf..3324ba8d8523c 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1699,6 +1699,8 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
>
> #define HAS_ASYNC_FLIPS(i915) (DISPLAY_VER(i915) >= 5)
>
> +#define HAS_FRONTBUFFER_RENDERING(i915) (DISPLAY_VER(i915) < 9)
> +
> /* Only valid when HAS_DISPLAY() is true */
> #define INTEL_DISPLAY_ENABLED(dev_priv) \
> (drm_WARN_ON(&(dev_priv)->drm, !HAS_DISPLAY(dev_priv)), !(dev_priv)->params.disable_display)
> --
> 2.33.0
--
Ville Syrjälä
Intel
