[PATCH v3 08/13] rpmsg: qcom_smd: Use qcom_smem_is_available()

From: Stephan Gerhold
Date: Thu Jun 15 2023 - 12:51:57 EST


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.

Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
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);

--
2.40.1