Hi Sean,
On Mon, Aug 05, 2019 at 01:01:20PM -0400, Sean Paul wrote:
On Sun, Aug 04, 2019 at 10:16:35PM +0200, Sam Ravnborg wrote:
Many panel drivers duplicate logic to prevent prepare to be called for a panel that is already prepared. Likewise for enable.
Implement this logic in drm_panel so the individual drivers no longer needs this. A panel is considered prepared/enabled only if the prepare/enable call succeeds. For disable/unprepare it is unconditionally considered disabled/unprepared.
Hi Sam, I did a similar thing a few years ago [1]. IIRC it was well received and just needed some nits cleaned up. Unfortunately I lost interest^W^W switched to other things and dropped it. So thanks for picking this back up!
Fast forward to today, I still think it's a good idea but I want to make sure this won't negatively interact with the self refresh helpers. With the helpers in place, it's possible to call disable consecutively (ie: once to enter self refresh and again to actually shut down). I did a quick pass and it looks like this patch might break that behavior, so you might want to take that into account.
Is this semantics documented somewhere ? The documentation of the panel disable operation is pretty terse, and we need to explicitly state who of the caller and callee needs to track the state.
[1]- https://patchwork.freedesktop.org/series/30712/
This allows calls to prepare/enable again, even if there were some issue disabling a regulator or similar during disable/unprepare.
Signed-off-by: Sam Ravnborg sam@ravnborg.org Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Maxime Ripard maxime.ripard@bootlin.com Cc: Sean Paul sean@poorly.run Cc: Thierry Reding thierry.reding@gmail.com Cc: Sam Ravnborg sam@ravnborg.org Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch
drivers/gpu/drm/drm_panel.c | 66 ++++++++++++++++++++++++++++++------- include/drm/drm_panel.h | 21 ++++++++++++ 2 files changed, 75 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index da19d5b4a2f4..0853764040de 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -66,10 +66,21 @@ EXPORT_SYMBOL(drm_panel_init); */ int drm_panel_prepare(struct drm_panel *panel) {
- if (panel && panel->funcs && panel->funcs->prepare)
return panel->funcs->prepare(panel);
- int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL;
- if (!panel)
return -EINVAL;- if (panel->prepared)
return 0;- if (panel->funcs && panel->funcs->prepare)
ret = panel->funcs->prepare(panel);- if (ret >= 0)
panel->prepared = true;- return ret;
} EXPORT_SYMBOL(drm_panel_prepare);
@@ -85,10 +96,21 @@ EXPORT_SYMBOL(drm_panel_prepare); */ int drm_panel_enable(struct drm_panel *panel) {
- if (panel && panel->funcs && panel->funcs->enable)
return panel->funcs->enable(panel);
- int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL;
- if (!panel)
return -EINVAL;- if (panel->enabled)
return 0;- if (panel->funcs && panel->funcs->enable)
ret = panel->funcs->enable(panel);- if (ret >= 0)
panel->enabled = true;- return ret;
} EXPORT_SYMBOL(drm_panel_enable);
@@ -104,10 +126,20 @@ EXPORT_SYMBOL(drm_panel_enable); */ int drm_panel_disable(struct drm_panel *panel) {
- if (panel && panel->funcs && panel->funcs->disable)
return panel->funcs->disable(panel);
- int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL;
- if (!panel)
return -EINVAL;- if (!panel->enabled)
return 0;- if (panel->funcs && panel->funcs->disable)
ret = panel->funcs->disable(panel);- panel->enabled = false;
- return ret;
} EXPORT_SYMBOL(drm_panel_disable);
@@ -124,10 +156,20 @@ EXPORT_SYMBOL(drm_panel_disable); */ int drm_panel_unprepare(struct drm_panel *panel) {
- if (panel && panel->funcs && panel->funcs->unprepare)
return panel->funcs->unprepare(panel);
- int ret = -ENOSYS;
- return panel ? -ENOSYS : -EINVAL;
- if (!panel)
return -EINVAL;- if (!panel->prepared)
return 0;- if (panel->funcs && panel->funcs->unprepare)
ret = panel->funcs->unprepare(panel);- panel->prepared = false;
- return ret;
} EXPORT_SYMBOL(drm_panel_unprepare);
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 624bd15ecfab..7493500fc9bd 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -65,6 +65,9 @@ struct drm_panel_funcs { * @prepare: * * Turn on panel and perform set up.
* When the panel is successfully prepared the prepare() function* will not be called again until the panel has been unprepared.*@@ -72,6 +75,8 @@ struct drm_panel_funcs { * @enable: * * Enable panel (turn on back light, etc.).
* When the panel is successfully enabled the enable() function* will not be called again until the panel has been disabled.@@ -79,6 +84,7 @@ struct drm_panel_funcs { * @disable: * * Disable panel (turn off back light, etc.).
* If the panel is already disabled the disable() function is not called.@@ -86,6 +92,7 @@ struct drm_panel_funcs { * @unprepare: * * Turn off panel.
* If the panel is already unprepared the unprepare() function is not called.@@ -145,6 +152,20 @@ struct drm_panel { * Panel entry in registry. */ struct list_head list;
- /**
* @prepared:** Set to true when the panel is successfully prepared.*/- bool prepared;
- /**
* @enabled:** Set to true when the panel is successfully enabled.*/- bool enabled;
};
void drm_panel_init(struct drm_panel *panel);