linux-kernel - [PATCH v4 35/78] drm/vc4: drv: Disable the CRTC at boot time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed,  8 Jul 2020 19:41:43 +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 v4 35/78] drm/vc4: drv: Disable the CRTC at boot time

In order to prevent issues during the firmware to KMS transition, we need
to make sure the pixelvalve are disabled at boot time so that the DRM state
matches the hardware state.

Reviewed-by: Eric Anholt <eric@...olt.net>
Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 25 +++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_drv.c  |  4 ++++
 drivers/gpu/drm/vc4/vc4_drv.h  |  1 +
 3 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 69851e19e2ab..a8bc3b26a0fb 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -411,6 +411,31 @@ static int vc4_crtc_disable(struct drm_crtc *crtc, unsigned int channel)
 	return 0;
 }
 
+int vc4_crtc_disable_at_boot(struct drm_crtc *crtc)
+{
+	struct drm_device *drm = crtc->dev;
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	int channel;
+
+	if (!(of_device_is_compatible(vc4_crtc->pdev->dev.of_node,
+				      "brcm,bcm2711-pixelvalve2") ||
+	      of_device_is_compatible(vc4_crtc->pdev->dev.of_node,
+				      "brcm,bcm2711-pixelvalve4")))
+		return 0;
+
+	if (!(CRTC_READ(PV_CONTROL) & PV_CONTROL_EN))
+		return 0;
+
+	if (!(CRTC_READ(PV_V_CONTROL) & PV_VCONTROL_VIDEN))
+		return 0;
+
+	channel = vc4_hvs_get_fifo_from_output(drm, vc4_crtc->data->hvs_output);
+	if (channel < 0)
+		return 0;
+
+	return vc4_crtc_disable(crtc, channel);
+}
+
 static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
 				    struct drm_crtc_state *old_state)
 {
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index 38343d2fb4fb..9567d1019212 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -252,6 +252,7 @@ static int vc4_drm_bind(struct device *dev)
 	struct drm_device *drm;
 	struct vc4_dev *vc4;
 	struct device_node *node;
+	struct drm_crtc *crtc;
 	int ret = 0;
 
 	dev->coherent_dma_mask = DMA_BIT_MASK(32);
@@ -298,6 +299,9 @@ static int vc4_drm_bind(struct device *dev)
 	if (ret < 0)
 		goto unbind_all;
 
+	drm_for_each_crtc(crtc, drm)
+		vc4_crtc_disable_at_boot(crtc);
+
 	ret = drm_dev_register(drm, 0);
 	if (ret < 0)
 		goto unbind_all;
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 860be019d8e3..1a97545b9244 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -813,6 +813,7 @@ void vc4_bo_remove_from_purgeable_pool(struct vc4_bo *bo);
 
 /* vc4_crtc.c */
 extern struct platform_driver vc4_crtc_driver;
+int vc4_crtc_disable_at_boot(struct drm_crtc *crtc);
 int vc4_crtc_init(struct drm_device *drm, struct vc4_crtc *vc4_crtc,
 		  const struct drm_crtc_funcs *crtc_funcs,
 		  const struct drm_crtc_helper_funcs *crtc_helper_funcs);
-- 
git-series 0.9.1