Re: [PATCH] remoteproc: mediatek: Refactor single core check and fix retrocompatibility

From: Mathieu Poirier
Date: Wed Sep 20 2023 - 09:29:04 EST


On Tue, Sep 19, 2023 at 11:23:36AM +0200, AngeloGioacchino Del Regno wrote:
> In older devicetrees we had the ChromeOS EC in a node called "cros-ec"
> instead of the newer "cros-ec-rpmsg", but this driver is now checking
> only for the latter, breaking compatibility with those.
>
> Besides, we can check if the SCP is single or dual core by simply
> walking through the children of the main SCP node and checking if
> if there's more than one "mediatek,scp-core" compatible node.
>
> Fixes: 1fdbf0cdde98 ("remoteproc: mediatek: Probe SCP cluster on multi-core SCP")
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> ---
> drivers/remoteproc/mtk_scp.c | 18 +++++++-----------
> 1 file changed, 7 insertions(+), 11 deletions(-)
>

I find this patch to be the most appropriate to fix this problem. Laura,
Chen-Yu and Tinghan, please test the patch and reply public with your Testeb-by
tags.

Thanks,
Mathieu

> diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> index ea227b566c54..a35409eda0cf 100644
> --- a/drivers/remoteproc/mtk_scp.c
> +++ b/drivers/remoteproc/mtk_scp.c
> @@ -1144,29 +1144,25 @@ static int scp_add_multi_core(struct platform_device *pdev,
> return ret;
> }
>
> -static int scp_is_single_core(struct platform_device *pdev)
> +static bool scp_is_single_core(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct device_node *np = dev_of_node(dev);
> struct device_node *child;
> + int num_cores = 0;
>
> - child = of_get_next_available_child(np, NULL);
> - if (!child)
> - return dev_err_probe(dev, -ENODEV, "No child node\n");
> + for_each_child_of_node(np, child)
> + if (of_device_is_compatible(child, "mediatek,scp-core"))
> + num_cores++;
>
> - of_node_put(child);
> - return of_node_name_eq(child, "cros-ec-rpmsg");
> + return num_cores < 2;
> }
>
> static int scp_cluster_init(struct platform_device *pdev, struct mtk_scp_of_cluster *scp_cluster)
> {
> int ret;
>
> - ret = scp_is_single_core(pdev);
> - if (ret < 0)
> - return ret;
> -
> - if (ret)
> + if (scp_is_single_core(pdev))
> ret = scp_add_single_core(pdev, scp_cluster);
> else
> ret = scp_add_multi_core(pdev, scp_cluster);
> --
> 2.42.0
>