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Message-ID: <70376b4f-0fbe-4087-8c7c-eb7167191a37@foss.st.com>
Date: Fri, 15 Dec 2023 17:55:38 +0100
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MIME-Version: 1.0
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Subject: Re: [PATCH V2] remoteproc: virtio: Fix wdg cannot recovery remote
 processor
Content-Language: en-US
To: <joakim.zhang@cixtech.com>, <andersson@kernel.org>,
        <mathieu.poirier@linaro.org>
CC: <linux-remoteproc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <cix-kernel-upstream@cixtech.com>
References: <20231215145023.2248366-1-joakim.zhang@cixtech.com>
From: Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>
Organization: STMicroelectronics
In-Reply-To: <20231215145023.2248366-1-joakim.zhang@cixtech.com>
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Hello  Joakim,

On 12/15/23 15:50, joakim.zhang@cixtech.com wrote:
> From: Joakim Zhang <joakim.zhang@cixtech.com>
> 
> Recovery remote processor failed when wdg irq received:
> [    0.842574] remoteproc remoteproc0: crash detected in cix-dsp-rproc: type watchdog
> [    0.842750] remoteproc remoteproc0: handling crash #1 in cix-dsp-rproc
> [    0.842824] remoteproc remoteproc0: recovering cix-dsp-rproc
> [    0.843342] remoteproc remoteproc0: stopped remote processor cix-dsp-rproc
> [    0.847901] rproc-virtio rproc-virtio.0.auto: Failed to associate buffer
> [    0.847979] remoteproc remoteproc0: failed to probe subdevices for cix-dsp-rproc: -16
> 
> The reason is that dma coherent mem would not be released when
> recovering the remote processor, due to rproc_virtio_remove()
> would not be called, where the mem released. It will fail when
> it try to allocate and associate buffer again.
> 
> We can see that dma coherent mem allocated from rproc_add_virtio_dev(),
> so should release it from rproc_remove_virtio_dev(). These functions should
> appear symmetrically:
> -rproc_vdev_do_start()->rproc_add_virtio_dev()->dma_declare_coherent_memory()
> -rproc_vdev_do_stop()->rproc_remove_virtio_dev()->dma_release_coherent_memory()
> 
> The same for of_reserved_mem_device_init_by_idx() and of_reserved_mem_device_release().
> 
> Fixes: 1d7b61c06dc3 ("remoteproc: virtio: Create platform device for the remoteproc_virtio")
> Signed-off-by: Joakim Zhang <joakim.zhang@cixtech.com>
> ---
> ChangeLogs:
> V1->V2:
>         * the same for of_reserved_mem_device_release()
> ---
>  drivers/remoteproc/remoteproc_virtio.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
> index 83d76915a6ad..e877ee78740d 100644
> --- a/drivers/remoteproc/remoteproc_virtio.c
> +++ b/drivers/remoteproc/remoteproc_virtio.c
> @@ -465,8 +465,12 @@ static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
>  static int rproc_remove_virtio_dev(struct device *dev, void *data)
>  {
>         struct virtio_device *vdev = dev_to_virtio(dev);
> +       struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
> 
>         unregister_virtio_device(vdev);
> +       of_reserved_mem_device_release(&rvdev->pdev->dev);
> +       dma_release_coherent_memory(&rvdev->pdev->dev);
> +

At this step, the virtio device may not be released and may still be using the
memory.
Do you try to move this in rproc_virtio_dev_release?

Regards,
Arnaud

>         return 0;
>  }
> 
> @@ -584,9 +588,6 @@ static void rproc_virtio_remove(struct platform_device *pdev)
>         rproc_remove_subdev(rproc, &rvdev->subdev);
>         rproc_remove_rvdev(rvdev);
> 
> -       of_reserved_mem_device_release(&pdev->dev);
> -       dma_release_coherent_memory(&pdev->dev);
> -
>         put_device(&rproc->dev);
>  }
> 
> --
> 2.25.1
> 
> 
> 
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