Re: [PATCH 02/10] Revert "drm/msm: Fix failure paths in msm_drm_init()"

Dmitry Baryshkov
2023-03-28T12:50:28Z

On 06/03/2023 12:07, Johan Hovold wrote:
> This reverts commit 8636500300a01740d92b345c680b036b94555b1b.
>
> A recent commit tried to address a drm device leak in the early
> msm_drm_uninit() error paths but ended up making things worse.
>
> Specifically, it moved the drm device reference put in msm_drm_uninit()
> to msm_drm_init() which means that the drm would now be leaked on normal
> unbind.
>
> For reasons that were never spelled out, it also added kms NULL pointer
> checks to a couple of helper functions that had nothing to do with the
> paths modified by the patch.
>
> Instead of trying to salvage this incrementally, let's revert the bad
> commit so that clean and backportable fixes can be added in its place.
>
> Fixes: 8636500300a0 ("drm/msm: Fix failure paths in msm_drm_init()")
> Cc: Akhil P Oommen <quic_akhilpo@quicinc.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Ok, let's do it this way

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> ---
> drivers/gpu/drm/msm/disp/msm_disp_snapshot.c | 3 ---
> drivers/gpu/drm/msm/msm_drv.c | 11 ++++-------
> 2 files changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot.c
> index b73031cd48e4..e75b97127c0d 100644
> --- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot.c
> +++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot.c
> @@ -129,9 +129,6 @@ void msm_disp_snapshot_destroy(struct drm_device *drm_dev)
> }
>
> priv = drm_dev->dev_private;
> - if (!priv->kms)
> - return;
> -
> kms = priv->kms;
>
> if (kms->dump_worker)
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index b7f5a78eadd4..9ded384acba4 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -150,9 +150,6 @@ static void msm_irq_uninstall(struct drm_device *dev)
> struct msm_drm_private *priv = dev->dev_private;
> struct msm_kms *kms = priv->kms;
>
> - if (!priv->kms)
> - return;
> -
> kms->funcs->irq_uninstall(kms);
> if (kms->irq_requested)
> free_irq(kms->irq, dev);
> @@ -270,6 +267,8 @@ static int msm_drm_uninit(struct device *dev)
> component_unbind_all(dev, ddev);
>
> ddev->dev_private = NULL;
> + drm_dev_put(ddev);
> +
> destroy_workqueue(priv->wq);
>
> return 0;
> @@ -442,12 +441,12 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>
> ret = msm_init_vram(ddev);
> if (ret)
> - goto err_drm_dev_put;
> + return ret;
>
> /* Bind all our sub-components: */
> ret = component_bind_all(dev, ddev);
> if (ret)
> - goto err_drm_dev_put;
> + return ret;
>
> dma_set_max_seg_size(dev, UINT_MAX);
>
> @@ -542,8 +541,6 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>
> err_msm_uninit:
> msm_drm_uninit(dev);
> -err_drm_dev_put:
> - drm_dev_put(ddev);
> return ret;
> }
>

--
With best wishes
Dmitry