linux-kernel - [PATCH v3 062/105] drm/vc4: crtc: Only access the PixelValve registers if we have to

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Date:   Wed, 27 May 2020 17:48:32 +0200
From:   Maxime Ripard <maxime@...no.tech>
To:     Nicolas Saenz Julienne <nsaenzjulienne@...e.de>,
        Eric Anholt <eric@...olt.net>
Cc:     dri-devel@...ts.freedesktop.org,
        linux-rpi-kernel@...ts.infradead.org,
        bcm-kernel-feedback-list@...adcom.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Dave Stevenson <dave.stevenson@...pberrypi.com>,
        Tim Gover <tim.gover@...pberrypi.com>,
        Phil Elwell <phil@...pberrypi.com>,
        Maxime Ripard <maxime@...no.tech>
Subject: [PATCH v3 062/105] drm/vc4: crtc: Only access the PixelValve registers if we have to

The CRTC hooks are called both for the TXP and the pixelvalve, yet some
will read / write the registers as if the device was a pixelvalve, which
won't really work.

Let's make sure we only access those registers if we are running on a
PixelValve.

Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index f82e3b0e11bd..ee4381c144a5 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -405,16 +405,19 @@ static void require_hvs_enabled(struct drm_device *dev)
 
 static int vc4_crtc_disable(struct drm_crtc *crtc, unsigned int channel)
 {
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
 	struct drm_encoder *encoder = vc4_get_crtc_encoder(crtc);
 	struct vc4_encoder *vc4_encoder = to_vc4_encoder(encoder);
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 	struct drm_device *dev = crtc->dev;
 	int ret;
 
-	CRTC_WRITE(PV_V_CONTROL,
-		   CRTC_READ(PV_V_CONTROL) & ~PV_VCONTROL_VIDEN);
-	ret = wait_for(!(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_VIDEN), 1);
-	WARN_ONCE(ret, "Timeout waiting for !PV_VCONTROL_VIDEN\n");
+	if (!vc4_state->feed_txp) {
+		CRTC_WRITE(PV_V_CONTROL,
+			   CRTC_READ(PV_V_CONTROL) & ~PV_VCONTROL_VIDEN);
+		ret = wait_for(!(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_VIDEN), 1);
+		WARN_ONCE(ret, "Timeout waiting for !PV_VCONTROL_VIDEN\n");
+	}
 
 	mdelay(20);
 
@@ -508,10 +511,10 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
 	if (vc4_encoder->pre_crtc_configure)
 		vc4_encoder->pre_crtc_configure(encoder);
 
-	if (!vc4_state->feed_txp)
+	if (!vc4_state->feed_txp) {
 		vc4_crtc_config_pv(crtc);
-
-	CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_EN);
+		CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_EN);
+	}
 
 	if (vc4_encoder->pre_crtc_enable)
 		vc4_encoder->pre_crtc_enable(encoder);
@@ -611,6 +614,10 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crtc,
 static int vc4_enable_vblank(struct drm_crtc *crtc)
 {
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+
+	if (vc4_state->feed_txp)
+		return 0;
 
 	CRTC_WRITE(PV_INTEN, PV_INT_VFP_START);
 
@@ -620,6 +627,10 @@ static int vc4_enable_vblank(struct drm_crtc *crtc)
 static void vc4_disable_vblank(struct drm_crtc *crtc)
 {
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+
+	if (vc4_state->feed_txp)
+		return;
 
 	CRTC_WRITE(PV_INTEN, 0);
 }
-- 
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