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

Anastasia Belova abelova at astralinux.ru
Fri Aug 30 01:47:16 PDT 2024


Hi,

30/08/24 11:29, neil.armstrong at linaro.org пишет:
> On 30/08/2024 10:23, Anastasia Belova wrote:
>> Hi,
>>
>> 29/08/24 15:14, Neil Armstrong пишет:
>>> Hi,
>>>
>>> On 28/08/2024 13:04, Anastasia Belova wrote:
>>>> 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 where drm
>>>> dereferenced.
>>>
>>> Please send the fix separately with a Fixes tag.
>>>
>>
>> This fix can't be separated from the patch. drm_dev_put may be
>> removed only while switching to a managed drm. Otherwise
>> a check could be added before calling meson_encoder_*_remove.
>> But it would become redundant after switching to a managed drm.
>>
>> I may send the second version of this patch with Fixes tag, so all
>> changes could be applied to older versions.
>
> Reading the currenrt code, component_unbind_all(dev, drm) is called
> after drm_dev_put(drm), which is quite wrong aswell.
>
> So perhaps we should keep the kref on drm  until component_unbind_all()
> is called in the first case, no ?

Right, but with a managed drm we don't need to release kref ourselves.

The comment for commit is not complete. Information about dereference
of NULL in component_unbind_all may be added in the second version, as
well as Fixes tag.

Anastasia Belova

>
> Neil
>
>>
>> Thanks,
>> Anastasia Belova
>>
>>> Thanks,
>>> Neil
>>>
>>>>
>>>> Co-developed by Linux Verification Center (linuxtesting.org).
>>>>
>>>> Signed-off-by: Anastasia Belova <abelova at astralinux.ru>
>>>> ---
>>>>   drivers/gpu/drm/meson/meson_crtc.c         | 10 +--
>>>>   drivers/gpu/drm/meson/meson_drv.c          | 71 
>>>> ++++++++++------------
>>>>   drivers/gpu/drm/meson/meson_drv.h          |  2 +-
>>>>   drivers/gpu/drm/meson/meson_encoder_cvbs.c |  8 +--
>>>>   drivers/gpu/drm/meson/meson_overlay.c      |  8 +--
>>>>   drivers/gpu/drm/meson/meson_plane.c        | 10 +--
>>>>   6 files changed, 51 insertions(+), 58 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..2e7c2e7c7b82 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;
>>>> @@ -197,17 +196,13 @@ 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;
>>>> @@ -215,7 +210,7 @@ static int meson_drv_bind_master(struct device 
>>>> *dev, bool has_components)
>>>>       regs = devm_platform_ioremap_resource_byname(pdev, "vpu");
>>>>       if (IS_ERR(regs)) {
>>>>           ret = PTR_ERR(regs);
>>>> -        goto free_drm;
>>>> +        goto remove_encoders;
>>>>       }
>>>>         priv->io_base = regs;
>>>> @@ -223,13 +218,13 @@ static int meson_drv_bind_master(struct 
>>>> device *dev, bool has_components)
>>>>       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hhi");
>>>>       if (!res) {
>>>>           ret = -EINVAL;
>>>> -        goto free_drm;
>>>> +        goto remove_encoders;
>>>>       }
>>>>       /* 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;
>>>> +        goto remove_encoders;
>>>>       }
>>>>         priv->hhi = devm_regmap_init_mmio(dev, regs,
>>>> @@ -237,18 +232,18 @@ static int meson_drv_bind_master(struct 
>>>> device *dev, bool has_components)
>>>>       if (IS_ERR(priv->hhi)) {
>>>>           dev_err(&pdev->dev, "Couldn't create the HHI regmap\n");
>>>>           ret = PTR_ERR(priv->hhi);
>>>> -        goto free_drm;
>>>> +        goto remove_encoders;
>>>>       }
>>>>         priv->canvas = meson_canvas_get(dev);
>>>>       if (IS_ERR(priv->canvas)) {
>>>>           ret = PTR_ERR(priv->canvas);
>>>> -        goto free_drm;
>>>> +        goto remove_encoders;
>>>>       }
>>>>         ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_osd1);
>>>>       if (ret)
>>>> -        goto free_drm;
>>>> +        goto remove_encoders;
>>>>       ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_0);
>>>>       if (ret)
>>>>           goto free_canvas_osd1;
>>>> @@ -261,7 +256,7 @@ 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;
>>>>   @@ -284,10 +279,10 @@ static int meson_drv_bind_master(struct 
>>>> device *dev, bool has_components)
>>>>       ret = drmm_mode_config_init(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 +303,9 @@ 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;
>>>> @@ -339,26 +334,26 @@ static int meson_drv_bind_master(struct 
>>>> device *dev, bool has_components)
>>>>       if (ret)
>>>>           goto exit_afbcd;
>>>>   -    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;
>>>>   -    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);
>>>>   exit_afbcd:
>>>>       if (priv->afbcd.ops)
>>>>           priv->afbcd.ops->exit(priv);
>>>> @@ -370,15 +365,14 @@ 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);
>>>> +remove_encoders:
>>>>         meson_encoder_dsi_remove(priv);
>>>>       meson_encoder_hdmi_remove(priv);
>>>>       meson_encoder_cvbs_remove(priv);
>>>>         if (has_components)
>>>> -        component_unbind_all(dev, drm);
>>>> +        component_unbind_all(dev, &priv->drm);
>>>>         return ret;
>>>>   }
>>>> @@ -391,7 +385,7 @@ 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 +398,6 @@ 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 +421,7 @@ 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 +438,7 @@ 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 +448,8 @@ 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..c4c6c810cb20 100644
>>>> --- a/drivers/gpu/drm/meson/meson_drv.h
>>>> +++ b/drivers/gpu/drm/meson/meson_drv.h
>>>> @@ -53,7 +53,7 @@ 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_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;
>>>>       }
>>>
>>
>




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