linux-kernel - [PATCH v4 12/15] drm/panel-edp: hpd_reliable shouldn't be subtraced from hpd

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Date:   Thu,  9 Sep 2021 14:00:28 -0700
From:   Douglas Anderson <dianders@...omium.org>
To:     Thierry Reding <thierry.reding@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Sam Ravnborg <sam@...nborg.org>
Cc:     devicetree@...r.kernel.org, Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Linus W <linus.walleij@...aro.org>,
        Daniel Vetter <daniel@...ll.ch>, linux-arm-msm@...r.kernel.org,
        Steev Klimaszewski <steev@...i.org>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        David Airlie <airlied@...ux.ie>,
        dri-devel@...ts.freedesktop.org,
        Douglas Anderson <dianders@...omium.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v4 12/15] drm/panel-edp: hpd_reliable shouldn't be subtraced from hpd_absent

Now that the delays are named / described with eDP-centric names, it
becomes clear that we should really specify the "hpd_reliable" and
"hpd_absent" separately without taking the other into account. Let's
fix it.

This should be a no-op change and just adjust how we specify
things. The actual delays should be the same before and after for the
one panel that currently species both "hpd_reliable" and "hpd_absent".

Signed-off-by: Douglas Anderson <dianders@...omium.org>
Acked-by: Sam Ravnborg <sam@...nborg.org>
---

Changes in v4:
- panel-simple-edp => panel-edp

 drivers/gpu/drm/panel/panel-edp.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 1547e4797594..80a37a4e5750 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -423,7 +423,7 @@ static int panel_edp_prepare_once(struct panel_edp *p)
 
 	delay = p->desc->delay.hpd_reliable;
 	if (p->no_hpd)
-		delay += p->desc->delay.hpd_absent;
+		delay = max(delay, p->desc->delay.hpd_absent);
 	if (delay)
 		msleep(delay);
 
@@ -1039,15 +1039,13 @@ static const struct panel_desc boe_nv133fhm_n61 = {
 		 * spike on the HPD line.  It was explained that this spike
 		 * was until the TCON data download was complete.  On
 		 * one system this was measured at 8 ms.  We'll put 15 ms
-		 * in the prepare delay just to be safe and take it away
-		 * from the hpd_absent (which would otherwise be 200 ms)
-		 * to handle this.  That means:
+		 * in the prepare delay just to be safe.  That means:
 		 * - If HPD isn't hooked up you still have 200 ms delay.
 		 * - If HPD is hooked up we won't try to look at it for the
 		 *   first 15 ms.
 		 */
 		.hpd_reliable = 15,
-		.hpd_absent = 185,
+		.hpd_absent = 200,
 
 		.unprepare = 500,
 	},
-- 
2.33.0.309.g3052b89438-goog