[Freedreno] [PATCH v2 01/13] drm/msm/dsi: switch to devm_drm_bridge_add()

[Dmitry Baryshkov]

On 09/10/2023 21:51, Abhinav Kumar wrote:
> 
> 
> On 10/9/2023 11:46 AM, Dmitry Baryshkov wrote:
>> On 09/10/2023 21:39, Abhinav Kumar wrote:
>>>
>>>
>>> On 10/9/2023 11:10 AM, Dmitry Baryshkov wrote:
>>>> Make MSM DSI driver use devm_drm_bridge_add() instead of plain
>>>> drm_bridge_add(). As the driver doesn't require any additional cleanup,
>>>> stop adding created bridge to the priv->bridges array.
>>>>
>>>> Reviewed-by: Rob Clark <robdclark at gmail.com>
>>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>>>> ---
>>>>   drivers/gpu/drm/msm/dsi/dsi.c         | 28 +++++--------------------
>>>>   drivers/gpu/drm/msm/dsi/dsi.h         |  3 +--
>>>>   drivers/gpu/drm/msm/dsi/dsi_manager.c | 30 
>>>> +++++++++------------------
>>>>   3 files changed, 16 insertions(+), 45 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi.c 
>>>> b/drivers/gpu/drm/msm/dsi/dsi.c
>>>> index d45e43024802..47f327e68471 100644
>>>> --- a/drivers/gpu/drm/msm/dsi/dsi.c
>>>> +++ b/drivers/gpu/drm/msm/dsi/dsi.c
>>>> @@ -215,20 +215,14 @@ void __exit msm_dsi_unregister(void)
>>>>   int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct 
>>>> drm_device *dev,
>>>>                struct drm_encoder *encoder)
>>>>   {
>>>> -    struct msm_drm_private *priv = dev->dev_private;
>>>>       int ret;
>>>> -    if (priv->num_bridges == ARRAY_SIZE(priv->bridges)) {
>>>> -        DRM_DEV_ERROR(dev->dev, "too many bridges\n");
>>>> -        return -ENOSPC;
>>>> -    }
>>>> -
>>>>       msm_dsi->dev = dev;
>>>>       ret = msm_dsi_host_modeset_init(msm_dsi->host, dev);
>>>>       if (ret) {
>>>>           DRM_DEV_ERROR(dev->dev, "failed to modeset init host: 
>>>> %d\n", ret);
>>>> -        goto fail;
>>>> +        return ret;
>>>>       }
>>>>       if (msm_dsi_is_bonded_dsi(msm_dsi) &&
>>>> @@ -242,32 +236,20 @@ int msm_dsi_modeset_init(struct msm_dsi 
>>>> *msm_dsi, struct drm_device *dev,
>>>>       msm_dsi->encoder = encoder;
>>>> -    msm_dsi->bridge = msm_dsi_manager_bridge_init(msm_dsi->id);
>>>> -    if (IS_ERR(msm_dsi->bridge)) {
>>>> -        ret = PTR_ERR(msm_dsi->bridge);
>>>> +    ret = msm_dsi_manager_bridge_init(msm_dsi);
>>>> +    if (ret) {
>>>>           DRM_DEV_ERROR(dev->dev, "failed to create dsi bridge: 
>>>> %d\n", ret);
>>>> -        msm_dsi->bridge = NULL;
>>>> -        goto fail;
>>>> +        return ret;
>>>>       }
>>>>       ret = msm_dsi_manager_ext_bridge_init(msm_dsi->id);
>>>>       if (ret) {
>>>>           DRM_DEV_ERROR(dev->dev,
>>>>               "failed to create dsi connector: %d\n", ret);
>>>> -        goto fail;
>>>> +        return ret;
>>>>       }
>>>> -    priv->bridges[priv->num_bridges++]       = msm_dsi->bridge;
>>>> -
>>>>       return 0;
>>>> -fail:
>>>> -    /* bridge/connector are normally destroyed by drm: */
>>>> -    if (msm_dsi->bridge) {
>>>> -        msm_dsi_manager_bridge_destroy(msm_dsi->bridge);
>>>> -        msm_dsi->bridge = NULL;
>>>> -    }
>>>
>>> We can drop msm_dsi_manager_bridge_destroy() now but dont we need to 
>>> keep the part to reset msm_dsi->bridge to NULL in the fail tag if 
>>> msm_dsi_manager_ext_bridge_init() fails?
>>
>> What for? This field is not read in the error /unbinding path.
>> I'll send a followup that drops msm_dsi->bridge completely.
>>
> 
> Not used in the error path. The behavior before this patch was, if 
> msm_dsi_manager_ext_bridge_init failed, it was marking msm_dsi->bridge 
> as NULL. Thats what I thought you would want to retain till you drop the 
> msm_dsi->bridge.

Why would you like to keep the useless behaviour?

> OR you can even add that line in the if (ret) of 
> msm_dsi_manager_ext_bridge_init(msm_dsi->id); failure.
> 
>>>
>>>> -
>>>> -    return ret;
>>>>   }
>>>>   void msm_dsi_snapshot(struct msm_disp_state *disp_state, struct 
>>>> msm_dsi *msm_dsi)
>>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi.h 
>>>> b/drivers/gpu/drm/msm/dsi/dsi.h
>>>> index d21867da78b8..a01c326774a6 100644
>>>> --- a/drivers/gpu/drm/msm/dsi/dsi.h
>>>> +++ b/drivers/gpu/drm/msm/dsi/dsi.h
>>>> @@ -56,8 +56,7 @@ struct msm_dsi {
>>>>   };
>>>>   /* dsi manager */
>>>> -struct drm_bridge *msm_dsi_manager_bridge_init(u8 id);
>>>> -void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge);
>>>> +int msm_dsi_manager_bridge_init(struct msm_dsi *msm_dsi);
>>>>   int msm_dsi_manager_ext_bridge_init(u8 id);
>>>>   int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg);
>>>>   bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len);
>>>> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c 
>>>> b/drivers/gpu/drm/msm/dsi/dsi_manager.c
>>>> index 28b8012a21f2..17aa19bb6510 100644
>>>> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
>>>> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
>>>> @@ -466,9 +466,8 @@ static const struct drm_bridge_funcs 
>>>> dsi_mgr_bridge_funcs = {
>>>>   };
>>>>   /* initialize bridge */
>>>> -struct drm_bridge *msm_dsi_manager_bridge_init(u8 id)
>>>> +int msm_dsi_manager_bridge_init(struct msm_dsi *msm_dsi)
>>>>   {
>>>> -    struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
>>>>       struct drm_bridge *bridge = NULL;
>>>>       struct dsi_bridge *dsi_bridge;
>>>>       struct drm_encoder *encoder;
>>>> @@ -476,31 +475,27 @@ struct drm_bridge 
>>>> *msm_dsi_manager_bridge_init(u8 id)
>>>>       dsi_bridge = devm_kzalloc(msm_dsi->dev->dev,
>>>>                   sizeof(*dsi_bridge), GFP_KERNEL);
>>>> -    if (!dsi_bridge) {
>>>> -        ret = -ENOMEM;
>>>> -        goto fail;
>>>> -    }
>>>> +    if (!dsi_bridge)
>>>> +        return -ENOMEM;
>>>> -    dsi_bridge->id = id;
>>>> +    dsi_bridge->id = msm_dsi->id;
>>>>       encoder = msm_dsi->encoder;
>>>>       bridge = &dsi_bridge->base;
>>>>       bridge->funcs = &dsi_mgr_bridge_funcs;
>>>> -    drm_bridge_add(bridge);
>>>> +    ret = devm_drm_bridge_add(&msm_dsi->pdev->dev, bridge);
>>>> +    if (ret)
>>>> +        return ret;
>>>>       ret = drm_bridge_attach(encoder, bridge, NULL, 0);
>>>>       if (ret)
>>>> -        goto fail;
>>>> +        return ret;
>>>> -    return bridge;
>>>> +    msm_dsi->bridge = bridge;
>>>> -fail:
>>>> -    if (bridge)
>>>> -        msm_dsi_manager_bridge_destroy(bridge);
>>>> -
>>>> -    return ERR_PTR(ret);
>>>> +    return 0;
>>>>   }
>>>>   int msm_dsi_manager_ext_bridge_init(u8 id)
>>>> @@ -557,11 +552,6 @@ int msm_dsi_manager_ext_bridge_init(u8 id)
>>>>       return 0;
>>>>   }
>>>> -void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge)
>>>> -{
>>>> -    drm_bridge_remove(bridge);
>>>> -}
>>>> -
>>>>   int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg)
>>>>   {
>>>>       struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
>>

-- 
With best wishes
Dmitry