Commit 1452c25b authored by Sean Paul's avatar Sean Paul
Browse files

drm: Add helpers to kick off self refresh mode in drivers 

This patch adds a new drm helper library to help drivers implement
self refresh. Drivers choosing to use it will register crtcs and
will receive callbacks when it's time to enter or exit self refresh
mode.

In its current form, it has a timer which will trigger after a
driver-specified amount of inactivity. When the timer triggers, the
helpers will submit a new atomic commit to shut the refreshing pipe
off. On the next atomic commit, the drm core will revert the self
refresh state and bring everything back up to be actively driven.

From the driver's perspective, this works like a regular disable/enable
cycle. The driver need only check the 'self_refresh_active' state in
crtc_state. It should initiate self refresh mode on the panel and enter
an off or low-power state.

Changes in v2:
- s/psr/self_refresh/ (Daniel)
- integrated the psr exit into the commit that wakes it up (Jose/Daniel)
- made the psr state per-crtc (Jose/Daniel)
Changes in v3:
- Remove the self_refresh_(active|changed) from connector state (Daniel)
- Simplify loop in drm_self_refresh_helper_alter_state (Daniel)
- Improve self_refresh_aware comment (Daniel)
- s/self_refresh_state/self_refresh_data/ (Daniel)
Changes in v4:
- Move docbook location below panel (Daniel)
- Improve docbook with references and more detailed explanation (Daniel)
- Instead of register/unregister, use init/cleanup (Daniel)
Changes in v5:
- Resolved conflict in drm_atomic_helper.c #include block
- Resolved conflict in rst with HDCP helper docs
Changes in v6:
- Fix include ordering, clean up forward declarations (Sam)

Link to v1: https://patchwork.freedesktop.org/patch/msgid/20190228210939.83386-2-sean@poorly.run
Link to v2: https://patchwork.freedesktop.org/patch/msgid/20190326204509.96515-1-sean@poorly.run
Link to v3: https://patchwork.freedesktop.org/patch/msgid/20190502194956.218441-6-sean@poorly.run
Link to v4: https://patchwork.freedesktop.org/patch/msgid/20190508160920.144739-6-sean@poorly.run
Link to v5: https://patchwork.freedesktop.org/patch/msgid/20190611160844.257498-6-sean@poorly.run



Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jose Souza <jose.souza@intel.com>
Cc: Zain Wang <wzz@rock-chips.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Reviewed-by: default avatarDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: default avatarSean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190612145026.191846-1-sean@poorly.run
parent 6f3b6278

Documentation/gpu/drm-kms-helpers.rst

+9 −0
Original line number Diff line number Diff line
@@ -181,6 +181,15 @@ Panel Helper Reference 
.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c

   :export:



Panel Self Refresh Helper Reference

===================================



.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c

   :doc: overview



.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c

   :export:



HDCP Helper Functions Reference

===============================

drivers/gpu/drm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper 
		drm_simple_kms_helper.o drm_modeset_helper.o \

		drm_scdc_helper.o drm_gem_framebuffer_helper.o \

		drm_atomic_state_helper.o drm_damage_helper.o \

		drm_format_helper.o

		drm_format_helper.o drm_self_refresh_helper.o



drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o

drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o

drivers/gpu/drm/drm_atomic.c

+2 −0
Original line number Diff line number Diff line
@@ -384,6 +384,7 @@ static void drm_atomic_crtc_print_state(struct drm_printer *p, 
	drm_printf(p, "crtc[%u]: %s\n", crtc->base.id, crtc->name);

	drm_printf(p, "\tenable=%d\n", state->enable);

	drm_printf(p, "\tactive=%d\n", state->active);

	drm_printf(p, "\tself_refresh_active=%d\n", state->self_refresh_active);

	drm_printf(p, "\tplanes_changed=%d\n", state->planes_changed);

	drm_printf(p, "\tmode_changed=%d\n", state->mode_changed);

	drm_printf(p, "\tactive_changed=%d\n", state->active_changed);
@@ -999,6 +1000,7 @@ static void drm_atomic_connector_print_state(struct drm_printer *p, 


	drm_printf(p, "connector[%u]: %s\n", connector->base.id, connector->name);

	drm_printf(p, "\tcrtc=%s\n", state->crtc ? state->crtc->name : "(null)");

	drm_printf(p, "\tself_refresh_aware=%d\n", state->self_refresh_aware);



	if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)

		if (state->writeback_job && state->writeback_job->fb)

drivers/gpu/drm/drm_atomic_helper.c

+33 −2
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <drm/drm_device.h>

#include <drm/drm_plane_helper.h>

#include <drm/drm_print.h>

#include <drm/drm_self_refresh_helper.h>

#include <drm/drm_vblank.h>

#include <drm/drm_writeback.h>
@@ -953,10 +954,33 @@ int drm_atomic_helper_check(struct drm_device *dev, 
	if (state->legacy_cursor_update)

		state->async_update = !drm_atomic_helper_async_check(dev, state);



	drm_self_refresh_helper_alter_state(state);



	return ret;

}

EXPORT_SYMBOL(drm_atomic_helper_check);



static bool

crtc_needs_disable(struct drm_crtc_state *old_state,

		   struct drm_crtc_state *new_state)

{

	/*

	 * No new_state means the crtc is off, so the only criteria is whether

	 * it's currently active or in self refresh mode.

	 */

	if (!new_state)

		return drm_atomic_crtc_effectively_active(old_state);



	/*

	 * We need to run through the crtc_funcs->disable() function if the crtc

	 * is currently on, if it's transitioning to self refresh mode, or if

	 * it's in self refresh mode and needs to be fully disabled.

	 */

	return old_state->active ||

	       (old_state->self_refresh_active && !new_state->enable) ||

	       new_state->self_refresh_active;

}



static void

disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)

{
@@ -977,7 +1001,14 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state) 


		old_crtc_state = drm_atomic_get_old_crtc_state(old_state, old_conn_state->crtc);



		if (!old_crtc_state->active ||

		if (new_conn_state->crtc)

			new_crtc_state = drm_atomic_get_new_crtc_state(

						old_state,

						new_conn_state->crtc);

		else

			new_crtc_state = NULL;



		if (!crtc_needs_disable(old_crtc_state, new_crtc_state) ||

		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))

			continue;
@@ -1023,7 +1054,7 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state) 
		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))

			continue;



		if (!old_crtc_state->active)

		if (!crtc_needs_disable(old_crtc_state, new_crtc_state))

			continue;



		funcs = crtc->helper_private;

drivers/gpu/drm/drm_atomic_state_helper.c

+4 −0
Original line number Diff line number Diff line
@@ -129,6 +129,10 @@ void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc, 
	state->commit = NULL;

	state->event = NULL;

	state->pageflip_flags = 0;



	/* Self refresh should be canceled when a new update is available */

	state->active = drm_atomic_crtc_effectively_active(state);

	state->self_refresh_active = false;

}

EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);

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