On 3/12/2025 4:42 PM, Rob Herring (Arm) 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) <r...@kernel.org>
> ---
> drivers/net/wireless/ath/ath10k/core.c | 22 ++++++----------------
> 1 file changed, 6 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/core.c
> b/drivers/net/wireless/ath/ath10k/core.c
> index b3294287bce1..db7444af251d 100644
> --- a/drivers/net/wireless/ath/ath10k/core.c
> +++ b/drivers/net/wireless/ath/ath10k/core.c
> @@ -1889,7 +1889,7 @@ 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;
>
> @@ -1900,28 +1900,18 @@ static int ath10k_download_cal_dt(struct ath10k *ar,
> const char *dt_name)
> */
> return -ENOENT;
>
> - if (!of_get_property(node, dt_name, &data_len)) {
> - /* The calibration data node is optional */
> - return -ENOENT;
> - }
note that there is one instance where .cal_data_len = 0
so i suggest that there still needs to be an early return here to avoid
kmalloc(0):
if (!data_len)
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) {
> - 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);
> goto out_free;
> }
>
this could made even cleaner using cleanup.h functionality (all of the gotos
could disappear). perhaps I'll do that as a follow-up patch on top of your
patch.
/jeff
