diff mbox

[v5,1/3] hwmon: iio_hwmon: defer probe when no channel is found

Message ID 1473344917-1524-2-git-send-email-quentin.schulz@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Quentin Schulz Sept. 8, 2016, 2:28 p.m. UTC
iio_channel_get_all returns -ENODEV when it cannot find either phandles and
properties in the Device Tree or channels whose consumer_dev_name matches
iio_hwmon in iio_map_list. The iio_map_list is filled in by iio drivers
which might be probed after iio_hwmon.

It is better to defer the probe of iio_hwmon if such error is returned by
iio_channel_get_all in order to let a chance to iio drivers to expose
channels in iio_map_list.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
---

v5:
 - patch re-inserted,

v3:
 - patch removed,

 drivers/hwmon/iio_hwmon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Guenter Roeck Sept. 9, 2016, 4:26 a.m. UTC | #1
On 09/08/2016 07:28 AM, Quentin Schulz wrote:
> iio_channel_get_all returns -ENODEV when it cannot find either phandles and
> properties in the Device Tree or channels whose consumer_dev_name matches
> iio_hwmon in iio_map_list. The iio_map_list is filled in by iio drivers
> which might be probed after iio_hwmon.
>
> It is better to defer the probe of iio_hwmon if such error is returned by
> iio_channel_get_all in order to let a chance to iio drivers to expose
> channels in iio_map_list.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
> ---
>
> v5:
>  - patch re-inserted,
>
Grumble ... applied to -next anyway.

I'll direct any complaints your way ;-)

Guenter
Jonathan Cameron Sept. 10, 2016, 3:02 p.m. UTC | #2
On 09/09/16 05:26, Guenter Roeck wrote:
> On 09/08/2016 07:28 AM, Quentin Schulz wrote:
>> iio_channel_get_all returns -ENODEV when it cannot find either phandles and
>> properties in the Device Tree or channels whose consumer_dev_name matches
>> iio_hwmon in iio_map_list. The iio_map_list is filled in by iio drivers
>> which might be probed after iio_hwmon.
>>
>> It is better to defer the probe of iio_hwmon if such error is returned by
>> iio_channel_get_all in order to let a chance to iio drivers to expose
>> channels in iio_map_list.
>>
>> Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
>> ---
>>
>> v5:
>>  - patch re-inserted,
>>
> Grumble ... applied to -next anyway.
> 
> I'll direct any complaints your way ;-)
> 
> Guenter
> 
Thanks.  I'll try and squeeze some time to look at a more general
solution (reworking how we set the maps up in the first place) if
no one else gets to it first!

It's on the list :)

Jonathan
diff mbox

Patch

diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
index b550ba5..c0da4d9 100644
--- a/drivers/hwmon/iio_hwmon.c
+++ b/drivers/hwmon/iio_hwmon.c
@@ -73,8 +73,11 @@  static int iio_hwmon_probe(struct platform_device *pdev)
 		name = dev->of_node->name;
 
 	channels = iio_channel_get_all(dev);
-	if (IS_ERR(channels))
+	if (IS_ERR(channels)) {
+		if (PTR_ERR(channels) == -ENODEV)
+			return -EPROBE_DEFER;
 		return PTR_ERR(channels);
+	}
 
 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
 	if (st == NULL) {