On 5.06.2023 09:08, Stephan Gerhold wrote:
> Rather than looking up a dummy item from SMEM, use the new
> qcom_smem_is_available() function to make the code more clear
> (and reduce the overhead slightly).
>
> Add the same check to qcom_smd_register_edge() as well to ensure that
> it only succeeds if SMEM is already available - if a driver calls the
> function and SMEM is not available yet then the initial state will be
> read incorrectly and the RPMSG devices might never become available.
>
> Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
> ---
> drivers/rpmsg/qcom_smd.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c
> index 7b9c298aa491..43f601c84b4f 100644
> --- a/drivers/rpmsg/qcom_smd.c
> +++ b/drivers/rpmsg/qcom_smd.c
> @@ -1479,6 +1479,9 @@ struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
> struct qcom_smd_edge *edge;
> int ret;
>
> + if (!qcom_smem_is_available())
> + return ERR_PTR(-EPROBE_DEFER);
> +
> edge = kzalloc(sizeof(*edge), GFP_KERNEL);
> if (!edge)
> return ERR_PTR(-ENOMEM);
> @@ -1553,12 +1556,9 @@ EXPORT_SYMBOL(qcom_smd_unregister_edge);
> static int qcom_smd_probe(struct platform_device *pdev)
> {
> struct device_node *node;
> - void *p;
>
> - /* Wait for smem */
> - p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
> - if (PTR_ERR(p) == -EPROBE_DEFER)
> - return PTR_ERR(p);
> + if (!qcom_smem_is_available())
> + return -EPROBE_DEFER;
>
> for_each_available_child_of_node(pdev->dev.of_node, node)
> qcom_smd_register_edge(&pdev->dev, node);
Hm.. we're not checking the return value here, at all.. Perhaps that
could be improved and we could only check for smem presence inside
qcom_smd_register_edge()?
Konrad
>
