[PATCH v4] drm/meson: switch to a managed drm device

From: Anastasia Belova
Date: Wed Oct 09 2024 - 09:16:51 EST


Switch to a managed drm device to cleanup some error handling
and make future work easier.

Fix dereference of NULL in meson_drv_bind_master by removing
drm_dev_put(drm) before meson_encoder_*_remove and
component_unbind_all where drm is dereferenced.

Co-developed by Linux Verification Center (linuxtesting.org).

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 6a044642988b ("drm/meson: fix unbind path if HDMI fails to bind")
Signed-off-by: Anastasia Belova <abelova@xxxxxxxxxxxxx>
---
v2: fix commit message and add Cc: stable@xxxxxxxxxxxxxxx
v3: cleanup error paths
v4: fix build errors
drivers/gpu/drm/meson/meson_crtc.c | 10 +--
drivers/gpu/drm/meson/meson_drv.c | 93 ++++++++++------------
drivers/gpu/drm/meson/meson_drv.h | 3 +-
drivers/gpu/drm/meson/meson_encoder_cvbs.c | 8 +-
drivers/gpu/drm/meson/meson_encoder_dsi.c | 2 +-
drivers/gpu/drm/meson/meson_encoder_hdmi.c | 4 +-
drivers/gpu/drm/meson/meson_overlay.c | 8 +-
drivers/gpu/drm/meson/meson_plane.c | 10 +--
8 files changed, 63 insertions(+), 75 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_crtc.c b/drivers/gpu/drm/meson/meson_crtc.c
index d70616da8ce2..e1c0bf3baeea 100644
--- a/drivers/gpu/drm/meson/meson_crtc.c
+++ b/drivers/gpu/drm/meson/meson_crtc.c
@@ -662,13 +662,13 @@ void meson_crtc_irq(struct meson_drm *priv)

drm_crtc_handle_vblank(priv->crtc);

- spin_lock_irqsave(&priv->drm->event_lock, flags);
+ spin_lock_irqsave(&priv->drm.event_lock, flags);
if (meson_crtc->event) {
drm_crtc_send_vblank_event(priv->crtc, meson_crtc->event);
drm_crtc_vblank_put(priv->crtc);
meson_crtc->event = NULL;
}
- spin_unlock_irqrestore(&priv->drm->event_lock, flags);
+ spin_unlock_irqrestore(&priv->drm.event_lock, flags);
}

int meson_crtc_create(struct meson_drm *priv)
@@ -677,18 +677,18 @@ int meson_crtc_create(struct meson_drm *priv)
struct drm_crtc *crtc;
int ret;

- meson_crtc = devm_kzalloc(priv->drm->dev, sizeof(*meson_crtc),
+ meson_crtc = devm_kzalloc(priv->drm.dev, sizeof(*meson_crtc),
GFP_KERNEL);
if (!meson_crtc)
return -ENOMEM;

meson_crtc->priv = priv;
crtc = &meson_crtc->base;
- ret = drm_crtc_init_with_planes(priv->drm, crtc,
+ ret = drm_crtc_init_with_planes(&priv->drm, crtc,
priv->primary_plane, NULL,
&meson_crtc_funcs, "meson_crtc");
if (ret) {
- dev_err(priv->drm->dev, "Failed to init CRTC\n");
+ dev_err(priv->drm.dev, "Failed to init CRTC\n");
return ret;
}

diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index 4bd0baa2a4f5..dd87c6b61e9e 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -182,7 +182,6 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
struct platform_device *pdev = to_platform_device(dev);
const struct meson_drm_match_data *match;
struct meson_drm *priv;
- struct drm_device *drm;
struct resource *res;
void __iomem *regs;
int ret, i;
@@ -197,58 +196,49 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
if (!match)
return -ENODEV;

- drm = drm_dev_alloc(&meson_driver, dev);
- if (IS_ERR(drm))
- return PTR_ERR(drm);
+ priv = devm_drm_dev_alloc(dev, &meson_driver,
+ struct meson_drm, drm);

- priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
- if (!priv) {
- ret = -ENOMEM;
- goto free_drm;
- }
- drm->dev_private = priv;
- priv->drm = drm;
+ if (IS_ERR(priv))
+ return PTR_ERR(priv);
+
+ priv->drm.dev_private = priv;
priv->dev = dev;
priv->compat = match->compat;
priv->afbcd.ops = match->afbcd_ops;

regs = devm_platform_ioremap_resource_byname(pdev, "vpu");
if (IS_ERR(regs)) {
- ret = PTR_ERR(regs);
- goto free_drm;
+ return PTR_ERR(regs);
}

priv->io_base = regs;

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hhi");
if (!res) {
- ret = -EINVAL;
- goto free_drm;
+ return -EINVAL;
}
/* Simply ioremap since it may be a shared register zone */
regs = devm_ioremap(dev, res->start, resource_size(res));
if (!regs) {
- ret = -EADDRNOTAVAIL;
- goto free_drm;
+ return -EADDRNOTAVAIL;
}

priv->hhi = devm_regmap_init_mmio(dev, regs,
&meson_regmap_config);
if (IS_ERR(priv->hhi)) {
dev_err(&pdev->dev, "Couldn't create the HHI regmap\n");
- ret = PTR_ERR(priv->hhi);
- goto free_drm;
+ return PTR_ERR(priv->hhi);
}

priv->canvas = meson_canvas_get(dev);
if (IS_ERR(priv->canvas)) {
- ret = PTR_ERR(priv->canvas);
- goto free_drm;
+ return PTR_ERR(priv->canvas);
}

ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_osd1);
if (ret)
- goto free_drm;
+ return ret;
ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_0);
if (ret)
goto free_canvas_osd1;
@@ -261,7 +251,7 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)

priv->vsync_irq = platform_get_irq(pdev, 0);

- ret = drm_vblank_init(drm, 1);
+ ret = drm_vblank_init(&priv->drm, 1);
if (ret)
goto free_canvas_vd1_2;

@@ -281,13 +271,13 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
if (ret)
goto free_canvas_vd1_2;

- ret = drmm_mode_config_init(drm);
+ ret = drmm_mode_config_init(&priv->drm);
if (ret)
goto free_canvas_vd1_2;
- drm->mode_config.max_width = 3840;
- drm->mode_config.max_height = 2160;
- drm->mode_config.funcs = &meson_mode_config_funcs;
- drm->mode_config.helper_private = &meson_mode_config_helpers;
+ priv->drm.mode_config.max_width = 3840;
+ priv->drm.mode_config.max_height = 2160;
+ priv->drm.mode_config.funcs = &meson_mode_config_funcs;
+ priv->drm.mode_config.helper_private = &meson_mode_config_helpers;

/* Hardware Initialization */

@@ -308,9 +298,9 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
goto exit_afbcd;

if (has_components) {
- ret = component_bind_all(dev, drm);
+ ret = component_bind_all(dev, &priv->drm);
if (ret) {
- dev_err(drm->dev, "Couldn't bind all components\n");
+ dev_err(priv->drm.dev, "Couldn't bind all components\n");
/* Do not try to unbind */
has_components = false;
goto exit_afbcd;
@@ -319,46 +309,49 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)

ret = meson_encoder_hdmi_probe(priv);
if (ret)
- goto exit_afbcd;
+ goto unbind_components;

if (meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A)) {
ret = meson_encoder_dsi_probe(priv);
if (ret)
- goto exit_afbcd;
+ goto unbind_components;
}

ret = meson_plane_create(priv);
if (ret)
- goto exit_afbcd;
+ goto unbind_components;

ret = meson_overlay_create(priv);
if (ret)
- goto exit_afbcd;
+ goto unbind_components;

ret = meson_crtc_create(priv);
if (ret)
- goto exit_afbcd;
+ goto unbind_components;

- ret = request_irq(priv->vsync_irq, meson_irq, 0, drm->driver->name, drm);
+ ret = request_irq(priv->vsync_irq, meson_irq, 0, priv->drm.driver->name, &priv->drm);
if (ret)
- goto exit_afbcd;
+ goto unbind_components;

- drm_mode_config_reset(drm);
+ drm_mode_config_reset(&priv->drm);

- drm_kms_helper_poll_init(drm);
+ drm_kms_helper_poll_init(&priv->drm);

platform_set_drvdata(pdev, priv);

- ret = drm_dev_register(drm, 0);
+ ret = drm_dev_register(&priv->drm, 0);
if (ret)
goto uninstall_irq;

- drm_fbdev_dma_setup(drm, 32);
+ drm_fbdev_dma_setup(&priv->drm, 32);

return 0;

uninstall_irq:
- free_irq(priv->vsync_irq, drm);
+ free_irq(priv->vsync_irq, &priv->drm);
+unbind_components:
+ if (has_components)
+ component_unbind_all(dev, &priv->drm);
exit_afbcd:
if (priv->afbcd.ops)
priv->afbcd.ops->exit(priv);
@@ -370,16 +363,11 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
meson_canvas_free(priv->canvas, priv->canvas_id_vd1_0);
free_canvas_osd1:
meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
-free_drm:
- drm_dev_put(drm);

meson_encoder_dsi_remove(priv);
meson_encoder_hdmi_remove(priv);
meson_encoder_cvbs_remove(priv);

- if (has_components)
- component_unbind_all(dev, drm);
-
return ret;
}

@@ -391,7 +379,7 @@ static int meson_drv_bind(struct device *dev)
static void meson_drv_unbind(struct device *dev)
{
struct meson_drm *priv = dev_get_drvdata(dev);
- struct drm_device *drm = priv->drm;
+ struct drm_device *drm = &priv->drm;

if (priv->canvas) {
meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
@@ -404,7 +392,6 @@ static void meson_drv_unbind(struct device *dev)
drm_kms_helper_poll_fini(drm);
drm_atomic_helper_shutdown(drm);
free_irq(priv->vsync_irq, drm);
- drm_dev_put(drm);

meson_encoder_dsi_remove(priv);
meson_encoder_hdmi_remove(priv);
@@ -428,7 +415,7 @@ static int __maybe_unused meson_drv_pm_suspend(struct device *dev)
if (!priv)
return 0;

- return drm_mode_config_helper_suspend(priv->drm);
+ return drm_mode_config_helper_suspend(&priv->drm);
}

static int __maybe_unused meson_drv_pm_resume(struct device *dev)
@@ -445,7 +432,7 @@ static int __maybe_unused meson_drv_pm_resume(struct device *dev)
if (priv->afbcd.ops)
priv->afbcd.ops->init(priv);

- return drm_mode_config_helper_resume(priv->drm);
+ return drm_mode_config_helper_resume(&priv->drm);
}

static void meson_drv_shutdown(struct platform_device *pdev)
@@ -455,8 +442,8 @@ static void meson_drv_shutdown(struct platform_device *pdev)
if (!priv)
return;

- drm_kms_helper_poll_fini(priv->drm);
- drm_atomic_helper_shutdown(priv->drm);
+ drm_kms_helper_poll_fini(&priv->drm);
+ drm_atomic_helper_shutdown(&priv->drm);
}

/*
diff --git a/drivers/gpu/drm/meson/meson_drv.h b/drivers/gpu/drm/meson/meson_drv.h
index 3f9345c14f31..45554c701322 100644
--- a/drivers/gpu/drm/meson/meson_drv.h
+++ b/drivers/gpu/drm/meson/meson_drv.h
@@ -8,6 +8,7 @@
#define __MESON_DRV_H

#include <linux/device.h>
+#include <drm/drm_device.h>
#include <linux/of.h>
#include <linux/regmap.h>

@@ -53,7 +54,7 @@ struct meson_drm {
u8 canvas_id_vd1_1;
u8 canvas_id_vd1_2;

- struct drm_device *drm;
+ struct drm_device drm;
struct drm_crtc *crtc;
struct drm_plane *primary_plane;
struct drm_plane *overlay_plane;
diff --git a/drivers/gpu/drm/meson/meson_encoder_cvbs.c b/drivers/gpu/drm/meson/meson_encoder_cvbs.c
index d1191de855d9..ddca22c8c1ff 100644
--- a/drivers/gpu/drm/meson/meson_encoder_cvbs.c
+++ b/drivers/gpu/drm/meson/meson_encoder_cvbs.c
@@ -104,7 +104,7 @@ static int meson_encoder_cvbs_get_modes(struct drm_bridge *bridge,
for (i = 0; i < MESON_CVBS_MODES_COUNT; ++i) {
struct meson_cvbs_mode *meson_mode = &meson_cvbs_modes[i];

- mode = drm_mode_duplicate(priv->drm, &meson_mode->mode);
+ mode = drm_mode_duplicate(&priv->drm, &meson_mode->mode);
if (!mode) {
dev_err(priv->dev, "Failed to create a new display mode\n");
return 0;
@@ -221,7 +221,7 @@ static const struct drm_bridge_funcs meson_encoder_cvbs_bridge_funcs = {

int meson_encoder_cvbs_probe(struct meson_drm *priv)
{
- struct drm_device *drm = priv->drm;
+ struct drm_device *drm = &priv->drm;
struct meson_encoder_cvbs *meson_encoder_cvbs;
struct drm_connector *connector;
struct device_node *remote;
@@ -256,7 +256,7 @@ int meson_encoder_cvbs_probe(struct meson_drm *priv)
meson_encoder_cvbs->priv = priv;

/* Encoder */
- ret = drm_simple_encoder_init(priv->drm, &meson_encoder_cvbs->encoder,
+ ret = drm_simple_encoder_init(&priv->drm, &meson_encoder_cvbs->encoder,
DRM_MODE_ENCODER_TVDAC);
if (ret)
return dev_err_probe(priv->dev, ret,
@@ -273,7 +273,7 @@ int meson_encoder_cvbs_probe(struct meson_drm *priv)
}

/* Initialize & attach Bridge Connector */
- connector = drm_bridge_connector_init(priv->drm, &meson_encoder_cvbs->encoder);
+ connector = drm_bridge_connector_init(&priv->drm, &meson_encoder_cvbs->encoder);
if (IS_ERR(connector))
return dev_err_probe(priv->dev, PTR_ERR(connector),
"Unable to create CVBS bridge connector\n");
diff --git a/drivers/gpu/drm/meson/meson_encoder_dsi.c b/drivers/gpu/drm/meson/meson_encoder_dsi.c
index 7816902f5907..03bb12c69863 100644
--- a/drivers/gpu/drm/meson/meson_encoder_dsi.c
+++ b/drivers/gpu/drm/meson/meson_encoder_dsi.c
@@ -132,7 +132,7 @@ int meson_encoder_dsi_probe(struct meson_drm *priv)
meson_encoder_dsi->priv = priv;

/* Encoder */
- ret = drm_simple_encoder_init(priv->drm, &meson_encoder_dsi->encoder,
+ ret = drm_simple_encoder_init(&priv->drm, &meson_encoder_dsi->encoder,
DRM_MODE_ENCODER_DSI);
if (ret)
return dev_err_probe(priv->dev, ret,
diff --git a/drivers/gpu/drm/meson/meson_encoder_hdmi.c b/drivers/gpu/drm/meson/meson_encoder_hdmi.c
index 0593a1cde906..4465d987f85b 100644
--- a/drivers/gpu/drm/meson/meson_encoder_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_encoder_hdmi.c
@@ -402,7 +402,7 @@ int meson_encoder_hdmi_probe(struct meson_drm *priv)
meson_encoder_hdmi->priv = priv;

/* Encoder */
- ret = drm_simple_encoder_init(priv->drm, &meson_encoder_hdmi->encoder,
+ ret = drm_simple_encoder_init(&priv->drm, &meson_encoder_hdmi->encoder,
DRM_MODE_ENCODER_TMDS);
if (ret) {
dev_err_probe(priv->dev, ret, "Failed to init HDMI encoder\n");
@@ -420,7 +420,7 @@ int meson_encoder_hdmi_probe(struct meson_drm *priv)
}

/* Initialize & attach Bridge Connector */
- meson_encoder_hdmi->connector = drm_bridge_connector_init(priv->drm,
+ meson_encoder_hdmi->connector = drm_bridge_connector_init(&priv->drm,
&meson_encoder_hdmi->encoder);
if (IS_ERR(meson_encoder_hdmi->connector)) {
ret = dev_err_probe(priv->dev,
diff --git a/drivers/gpu/drm/meson/meson_overlay.c b/drivers/gpu/drm/meson/meson_overlay.c
index 7f98de38842b..60ee7f758723 100644
--- a/drivers/gpu/drm/meson/meson_overlay.c
+++ b/drivers/gpu/drm/meson/meson_overlay.c
@@ -484,7 +484,7 @@ static void meson_overlay_atomic_update(struct drm_plane *plane,

interlace_mode = new_state->crtc->mode.flags & DRM_MODE_FLAG_INTERLACE;

- spin_lock_irqsave(&priv->drm->event_lock, flags);
+ spin_lock_irqsave(&priv->drm.event_lock, flags);

if ((fb->modifier & DRM_FORMAT_MOD_AMLOGIC_FBC(0, 0)) ==
DRM_FORMAT_MOD_AMLOGIC_FBC(0, 0)) {
@@ -717,7 +717,7 @@ static void meson_overlay_atomic_update(struct drm_plane *plane,

priv->viu.vd1_enabled = true;

- spin_unlock_irqrestore(&priv->drm->event_lock, flags);
+ spin_unlock_irqrestore(&priv->drm.event_lock, flags);

DRM_DEBUG_DRIVER("\n");
}
@@ -838,7 +838,7 @@ int meson_overlay_create(struct meson_drm *priv)

DRM_DEBUG_DRIVER("\n");

- meson_overlay = devm_kzalloc(priv->drm->dev, sizeof(*meson_overlay),
+ meson_overlay = devm_kzalloc(priv->drm.dev, sizeof(*meson_overlay),
GFP_KERNEL);
if (!meson_overlay)
return -ENOMEM;
@@ -846,7 +846,7 @@ int meson_overlay_create(struct meson_drm *priv)
meson_overlay->priv = priv;
plane = &meson_overlay->base;

- drm_universal_plane_init(priv->drm, plane, 0xFF,
+ drm_universal_plane_init(&priv->drm, plane, 0xFF,
&meson_overlay_funcs,
supported_drm_formats,
ARRAY_SIZE(supported_drm_formats),
diff --git a/drivers/gpu/drm/meson/meson_plane.c b/drivers/gpu/drm/meson/meson_plane.c
index b43ac61201f3..13be94309bf4 100644
--- a/drivers/gpu/drm/meson/meson_plane.c
+++ b/drivers/gpu/drm/meson/meson_plane.c
@@ -157,7 +157,7 @@ static void meson_plane_atomic_update(struct drm_plane *plane,
* Update Buffer
* Enable Plane
*/
- spin_lock_irqsave(&priv->drm->event_lock, flags);
+ spin_lock_irqsave(&priv->drm.event_lock, flags);

/* Check if AFBC decoder is required for this buffer */
if ((meson_vpu_is_compatible(priv, VPU_COMPATIBLE_GXM) ||
@@ -393,7 +393,7 @@ static void meson_plane_atomic_update(struct drm_plane *plane,

priv->viu.osd1_enabled = true;

- spin_unlock_irqrestore(&priv->drm->event_lock, flags);
+ spin_unlock_irqrestore(&priv->drm.event_lock, flags);
}

static void meson_plane_atomic_disable(struct drm_plane *plane,
@@ -536,7 +536,7 @@ int meson_plane_create(struct meson_drm *priv)
const uint64_t *format_modifiers = format_modifiers_default;
int ret;

- meson_plane = devm_kzalloc(priv->drm->dev, sizeof(*meson_plane),
+ meson_plane = devm_kzalloc(priv->drm.dev, sizeof(*meson_plane),
GFP_KERNEL);
if (!meson_plane)
return -ENOMEM;
@@ -549,14 +549,14 @@ int meson_plane_create(struct meson_drm *priv)
else if (meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A))
format_modifiers = format_modifiers_afbc_g12a;

- ret = drm_universal_plane_init(priv->drm, plane, 0xFF,
+ ret = drm_universal_plane_init(&priv->drm, plane, 0xFF,
&meson_plane_funcs,
supported_drm_formats,
ARRAY_SIZE(supported_drm_formats),
format_modifiers,
DRM_PLANE_TYPE_PRIMARY, "meson_primary_plane");
if (ret) {
- devm_kfree(priv->drm->dev, meson_plane);
+ devm_kfree(priv->drm.dev, meson_plane);
return ret;
}

--
2.43.0