From: Dumitru Ceclan <dumitru.ceclan@analog.com>

Move configurations regarding number of channels from
*_fw_parse_device_config to *_fw_parse_channel_config.

Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
---
 drivers/iio/adc/ad7173.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 8a95b1391826..699bc6970790 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -917,7 +917,23 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
 	struct device *dev = indio_dev->dev.parent;
 	struct iio_chan_spec *chan_arr, *chan;
 	unsigned int ain[2], chan_index = 0;
-	int ref_sel, ret;
+	int ref_sel, ret, num_channels;
+
+	num_channels = device_get_child_node_count(dev);
+
+	if (st->info->has_temp)
+		num_channels++;
+
+	if (num_channels == 0)
+		return dev_err_probe(dev, -ENODATA, "No channels specified\n");
+
+	if (num_channels > st->info->num_channels)
+		return dev_err_probe(dev, -EINVAL,
+			"Too many channels specified. Maximum is %d, not including temperature channel if supported.\n",
+			st->info->num_channels);
+
+	indio_dev->num_channels = num_channels;
+	st->num_channels = num_channels;
 
 	chan_arr = devm_kcalloc(dev, sizeof(*indio_dev->channels),
 				st->num_channels, GFP_KERNEL);
@@ -1012,7 +1028,6 @@ static int ad7173_fw_parse_device_config(struct iio_dev *indio_dev)
 {
 	struct ad7173_state *st = iio_priv(indio_dev);
 	struct device *dev = indio_dev->dev.parent;
-	unsigned int num_channels;
 	int ret;
 
 	st->regulators[0].supply = ad7173_ref_sel_str[AD7173_SETUP_REF_SEL_EXT_REF];
@@ -1071,16 +1086,6 @@ static int ad7173_fw_parse_device_config(struct iio_dev *indio_dev)
 
 	ad7173_sigma_delta_info.irq_line = ret;
 
-	num_channels = device_get_child_node_count(dev);
-
-	if (st->info->has_temp)
-		num_channels++;
-
-	if (num_channels == 0)
-		return dev_err_probe(dev, -ENODATA, "No channels specified\n");
-	indio_dev->num_channels = num_channels;
-	st->num_channels = num_channels;
-
 	return ad7173_fw_parse_channel_config(indio_dev);
 }
 

-- 
2.43.0

On Mon, Apr 1, 2024 at 10:10 AM Dumitru Ceclan via B4 Relay
<devnull+dumitru.ceclan.analog.com@kernel.org> wrote:
>
> From: Dumitru Ceclan <dumitru.ceclan@analog.com>
>
> Move configurations regarding number of channels from
> *_fw_parse_device_config to *_fw_parse_channel_config.
>
> Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
> ---

Commit messages need to explain _why_ the change is being made [1]. It
is not obvious to me why this needs to be moved.

[1]: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#the-canonical-patch-format

On 01/04/2024 22:39, David Lechner wrote:
> On Mon, Apr 1, 2024 at 10:10 AM Dumitru Ceclan via B4 Relay
> <devnull+dumitru.ceclan.analog.com@kernel.org> wrote:
>>
>> From: Dumitru Ceclan <dumitru.ceclan@analog.com>
>>
>> Move configurations regarding number of channels from
>> *_fw_parse_device_config to *_fw_parse_channel_config.
>>
>> Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
>> ---
> 
> Commit messages need to explain _why_ the change is being made [1]. It
> is not obvious to me why this needs to be moved.
> 
> [1]: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#the-canonical-patch-format


Jonathan Cameron:

"
> +	if (num_channels == 0)
> +		return dev_err_probe(dev, -ENODATA, "No channels specified\n");
> +	indio_dev->num_channels = num_channels;
> +	st->num_channels = num_channels;

I'm not seeing benefit of duplication here really and logically it feels like
a lot of this last chunk would sit better in ad7173_fw_parse_channel_config()

Perhaps that's a job for a future tidying up patch.
"
https://lore.kernel.org/all/20240303162148.3ad91aa2@jic23-huawei/

On Wed, Apr 3, 2024 at 5:01 AM Ceclan, Dumitru <mitrutzceclan@gmail.com> wrote:
>
> On 01/04/2024 22:39, David Lechner wrote:
> > On Mon, Apr 1, 2024 at 10:10 AM Dumitru Ceclan via B4 Relay
> > <devnull+dumitru.ceclan.analog.com@kernel.org> wrote:
> >>
> >> From: Dumitru Ceclan <dumitru.ceclan@analog.com>
> >>
> >> Move configurations regarding number of channels from
> >> *_fw_parse_device_config to *_fw_parse_channel_config.
> >>
> >> Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
> >> ---
> >
> > Commit messages need to explain _why_ the change is being made [1]. It
> > is not obvious to me why this needs to be moved.
> >
> > [1]: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#the-canonical-patch-format
>
>
> Jonathan Cameron:
>
> "
> > +     if (num_channels == 0)
> > +             return dev_err_probe(dev, -ENODATA, "No channels specified\n");
> > +     indio_dev->num_channels = num_channels;
> > +     st->num_channels = num_channels;
>
> I'm not seeing benefit of duplication here really and logically it feels like
> a lot of this last chunk would sit better in ad7173_fw_parse_channel_config()
>
> Perhaps that's a job for a future tidying up patch.
> "
> https://lore.kernel.org/all/20240303162148.3ad91aa2@jic23-huawei/
>

Thanks.

A Link: and Suggested-by: in the commit message with this info would
be a reasonable way to communicate this.

I looks like this is also adding an additional check "  if
(num_channels > st->info->num_channels)" in addition to moving
existing code. It would be helpful to have the reason for this in the
commit message as well.

With the suggested additions to the commit message...
Reviewed-by: David Lechner <dlechner@baylibre.com>