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

neil.armstrong at linaro.org neil.armstrong at linaro.org
Fri Aug 30 01:29:38 PDT 2024


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 ?

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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