On Fri 16 Apr 17:39 CDT 2021, Douglas Anderson wrote:
Historically simple-panel had code to make sure that if prepare() was called on an already-prepared panel that it was a no-op. Similarly if unprepare() was called on an already-unprepared panel it was also a no-op. Essentially it means that these functions always "forced" the value to be whatever the caller wanted it to be. You can see that the forcing behavior dates back at least as far as 2014 by looking at commit 613a633e7a56 ("drm/panel: simple: Add proper definition for prepare and unprepare").
Apparently the code supporting the historical behavior may not be needed [1] and prepare() / unprepare() are supposed to be balanced. Let's try removing it and see if anyone breaks! If they do then we can have a debate about whether we should change that code or revert this patch. :-) If nobody breaks then we've nicely saved a few lines of code and some complexity.
[1] https://lore.kernel.org/r/YHePsQgqOau1V5lD@pendragon.ideasonboard.com
Acked-by: Bjorn Andersson bjorn.andersson@linaro.org
Regards, Bjorn
Suggested-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Douglas Anderson dianders@chromium.org
(no changes since v1)
drivers/gpu/drm/panel/panel-simple.c | 14 -------------- 1 file changed, 14 deletions(-)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 5a2953c4ca44..a2c3008af7e5 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -176,8 +176,6 @@ struct panel_simple { bool enabled; bool no_hpd;
- bool prepared;
- ktime_t prepared_time; ktime_t unprepared_time;
@@ -355,18 +353,12 @@ static int panel_simple_suspend(struct device *dev)
static int panel_simple_unprepare(struct drm_panel *panel) {
struct panel_simple *p = to_panel_simple(panel); int ret;
/* Unpreparing when already unprepared is a no-op */
if (!p->prepared)
return 0;pm_runtime_mark_last_busy(panel->dev); ret = pm_runtime_put_autosuspend(panel->dev); if (ret < 0) return ret;
p->prepared = false;
return 0;
} @@ -475,18 +467,12 @@ static int panel_simple_prepare(struct drm_panel *panel) struct panel_simple *p = to_panel_simple(panel); int ret;
/* Preparing when already prepared is a no-op */
if (p->prepared)
return 0;ret = pm_runtime_get_sync(panel->dev); if (ret < 0) { pm_runtime_put_autosuspend(panel->dev); return ret; }
p->prepared = true;
return 0;
}
-- 2.31.1.368.gbe11c130af-goog