[PATCH] soc: ti: knav: Use of_property_read_variable_u32_array()

[PATCH] soc: ti: knav: Use of_property_read_variable_u32_array()

[Rob Herring (Arm)]

There's no need to get the length of an DT array property before
parsing the array. of_property_read_variable_u32_array() takes a minimum
and maximum length and returns the actual length (or error code).

This is part of a larger effort to remove callers of of_find_property()
and similar functions. of_find_property() leaks the DT struct property
and data pointers which is a problem for dynamically allocated nodes
which may be freed.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
 drivers/soc/ti/knav_dma.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
index 6023006685fc..fb0746d8caad 100644
--- a/drivers/soc/ti/knav_dma.c
+++ b/drivers/soc/ti/knav_dma.c
@@ -602,7 +602,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node)
 	unsigned max_tx_chan, max_rx_chan, max_rx_flow, max_tx_sched;
 	struct device_node *node = dma_node;
 	struct knav_dma_device *dma;
-	int ret, len, num_chan = 0;
+	int ret, num_chan = 0;
 	resource_size_t size;
 	u32 timeout;
 	u32 i;
@@ -615,25 +615,13 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node)
 	INIT_LIST_HEAD(&dma->list);
 	INIT_LIST_HEAD(&dma->chan_list);
 
-	if (!of_find_property(cloud, "ti,navigator-cloud-address", &len)) {
-		dev_err(kdev->dev, "unspecified navigator cloud addresses\n");
-		return -ENODEV;
-	}
-
-	dma->logical_queue_managers = len / sizeof(u32);
-	if (dma->logical_queue_managers > DMA_MAX_QMS) {
-		dev_warn(kdev->dev, "too many queue mgrs(>%d) rest ignored\n",
-			 dma->logical_queue_managers);
-		dma->logical_queue_managers = DMA_MAX_QMS;
-	}
-
-	ret = of_property_read_u32_array(cloud, "ti,navigator-cloud-address",
-					dma->qm_base_address,
-					dma->logical_queue_managers);
-	if (ret) {
+	ret = of_property_read_variable_u32_array(cloud, "ti,navigator-cloud-address",
+						  dma->qm_base_address, 1, DMA_MAX_QMS);
+	if (ret < 0) {
 		dev_err(kdev->dev, "invalid navigator cloud addresses\n");
 		return -ENODEV;
 	}
+	dma->logical_queue_managers = ret;
 
 	dma->reg_global	 = pktdma_get_regs(dma, node, 0, &size);
 	if (IS_ERR(dma->reg_global))
-- 
2.43.0

Re: [PATCH] soc: ti: knav: Use of_property_read_variable_u32_array()

[Nishanth Menon]

Hi Rob Herring (Arm),

On Wed, 31 Jul 2024 14:13:58 -0600, Rob Herring (Arm) wrote:
> There's no need to get the length of an DT array property before
> parsing the array. of_property_read_variable_u32_array() takes a minimum
> and maximum length and returns the actual length (or error code).
> 
> This is part of a larger effort to remove callers of of_find_property()
> and similar functions. of_find_property() leaks the DT struct property
> and data pointers which is a problem for dynamically allocated nodes
> which may be freed.
> 
> [...]

I have applied the following to branch ti-drivers-soc-next on [1].
Thank you!

[1/1] soc: ti: knav: Use of_property_read_variable_u32_array()
      commit: b2a0176620db7aa0aa77109d7a8b894755441079

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/ti/linux.git
-- 
Regards,
Nishanth Menon
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