On Sat, Mar 15, 2025 at 5:07 AM Jonas Gorski <jonas.gorski@xxxxxxxxx> wrote:
>
> 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.
Indeed. Thanks for catching that.
Rob
