Hi,
On Sat, Mar 15, 2025 at 12:39 AM Rob Herring (Arm) <robh@xxxxxxxxxx> wrote:
>
> There's no need to check the property presence and length before calling
> of_property_read_u8_array() as it will return an error if the property
> is missing or the length is too small. The return errno doesn't matter
> to the caller, so no change in behavior there.
>
> Change of_property_read_u8_array() to of_property_read_variable_u8_array()
> as the former allows properties to be longer than the requested length.
> Now the property has to be the exact length requested as the removed
> check required.
>
> This part of a larger effort to remove DT functions like
> of_get_property() and of_find_property() which return raw DT data
> having no reference counting.
>
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
> ---
> v2:
> - Add check that cal_data_len is non-zero
> ---
> drivers/net/wireless/ath/ath10k/core.c | 24 +++++++-----------------
> 1 file changed, 7 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
> index b3294287bce1..47206b171aa5 100644
> --- a/drivers/net/wireless/ath/ath10k/core.c
> +++ b/drivers/net/wireless/ath/ath10k/core.c
> @@ -1889,39 +1889,29 @@ static int ath10k_download_cal_file(struct ath10k *ar,
> static int ath10k_download_cal_dt(struct ath10k *ar, const char *dt_name)
> {
> struct device_node *node;
> - int data_len;
> + int data_len = ar->hw_params.cal_data_len;
> void *data;
> int ret;
>
> node = ar->dev->of_node;
> - if (!node)
> + if (!node || !data_len)
> /* Device Tree is optional, don't print any warnings if
> * there's no node for ath10k.
> */
> return -ENOENT;
>
> - if (!of_get_property(node, dt_name, &data_len)) {
> - /* The calibration data node is optional */
> - return -ENOENT;
> - }
> -
> - if (data_len != ar->hw_params.cal_data_len) {
> - ath10k_warn(ar, "invalid calibration data length in DT: %d\n",
> - data_len);
> - ret = -EMSGSIZE;
> - goto out;
> - }
> -
> data = kmalloc(data_len, GFP_KERNEL);
> if (!data) {
> ret = -ENOMEM;
> goto out;
> }
>
> - ret = of_property_read_u8_array(node, dt_name, data, data_len);
> + ret = of_property_read_variable_u8_array(node, dt_name, data, data_len, data_len);
> if (ret) {
of_property_read_u8_array() returns 0 on success, but
of_property_read_variable_u8_array() returns the number of elements
read on success, so this check needs to be ret < 0 now.
> - ath10k_warn(ar, "failed to read calibration data from DT: %d\n",
> - ret);
> + /* Don't warn if optional property not found */
> + if (ret != -EINVAL)
> + ath10k_warn(ar, "failed to read calibration data from DT: %d\n",
> + ret);
Best regards,
Jonas
