max1363 : Warnings from iio_sanity_check_avail_scan_masks()

max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

Hi,

After upgrading the kernel from 6.1 to 6.12 (also tested with
linux-next), I started seeing the following warnings on a board
populated with a Maxim MAX11601 ADC:

[    1.554029] max1363 1-0064: available_scan_mask 8 subset of 0. Never used
[    1.563627] max1363 1-0064: available_scan_mask 9 subset of 0. Never used
[    1.570439] max1363 1-0064: available_scan_mask 10 subset of 0. Never used
[    1.577328] max1363 1-0064: available_scan_mask 11 subset of 0. Never used
[    1.584226] max1363 1-0064: available_scan_mask 12 subset of 0. Never used
[    1.591119] max1363 1-0064: available_scan_mask 13 subset of 0. Never used
[    1.598013] max1363 1-0064: available_scan_mask 8 subset of 1. Never used
[    1.604817] max1363 1-0064: available_scan_mask 9 subset of 1. Never used
[    1.611623] max1363 1-0064: available_scan_mask 10 subset of 1. Never used
[    1.618516] max1363 1-0064: available_scan_mask 11 subset of 1. Never used
[    1.625403] max1363 1-0064: available_scan_mask 12 subset of 1. Never used
[    1.632293] max1363 1-0064: available_scan_mask 13 subset of 1. Never used
[    1.639201] max1363 1-0064: available_scan_mask 8 subset of 2. Never used
[    1.646002] max1363 1-0064: available_scan_mask 9 subset of 2. Never used
[    1.652802] max1363 1-0064: available_scan_mask 10 subset of 2. Never used
[    1.659691] max1363 1-0064: available_scan_mask 11 subset of 2. Never used
[    1.666582] max1363 1-0064: available_scan_mask 12 subset of 2. Never used
[    1.673478] max1363 1-0064: available_scan_mask 13 subset of 2. Never used
[    1.680382] max1363 1-0064: available_scan_mask 8 subset of 3. Never used
[    1.687183] max1363 1-0064: available_scan_mask 9 subset of 3. Never used
[    1.693984] max1363 1-0064: available_scan_mask 10 subset of 3. Never used
[    1.700871] max1363 1-0064: available_scan_mask 11 subset of 3. Never used
[    1.707758] max1363 1-0064: available_scan_mask 12 subset of 3. Never used
[    1.714645] max1363 1-0064: available_scan_mask 13 subset of 3. Never used
[    1.721532] max1363 1-0064: available_scan_mask 8 subset of 4. Never used
[    1.728332] max1363 1-0064: available_scan_mask 9 subset of 4. Never used
[    1.735134] max1363 1-0064: available_scan_mask 10 subset of 4. Never used
[    1.742022] max1363 1-0064: available_scan_mask 11 subset of 4. Never used
[    1.748908] max1363 1-0064: available_scan_mask 12 subset of 4. Never used
[    1.755796] max1363 1-0064: available_scan_mask 13 subset of 4. Never used
[    1.762683] max1363 1-0064: available_scan_mask 8 subset of 5. Never used
[    1.769484] max1363 1-0064: available_scan_mask 9 subset of 5. Never used
[    1.776283] max1363 1-0064: available_scan_mask 10 subset of 5. Never used
[    1.783171] max1363 1-0064: available_scan_mask 11 subset of 5. Never used
[    1.790065] max1363 1-0064: available_scan_mask 12 subset of 5. Never used
[    1.796955] max1363 1-0064: available_scan_mask 13 subset of 5. Never used
[    1.803846] max1363 1-0064: available_scan_mask 7 subset of 6. Never used
[    1.810646] max1363 1-0064: available_scan_mask 8 subset of 6. Never used
[    1.817446] max1363 1-0064: available_scan_mask 9 subset of 6. Never used
[    1.824246] max1363 1-0064: available_scan_mask 10 subset of 6. Never used
[    1.831164] max1363 1-0064: available_scan_mask 11 subset of 6. Never used
[    1.838053] max1363 1-0064: available_scan_mask 12 subset of 6. Never used
[    1.844941] max1363 1-0064: available_scan_mask 13 subset of 6. Never used
[    1.851828] max1363 1-0064: available_scan_mask 8 subset of 7. Never used
[    1.858627] max1363 1-0064: available_scan_mask 9 subset of 7. Never used
[    1.865424] max1363 1-0064: available_scan_mask 10 subset of 7. Never used
[    1.872311] max1363 1-0064: available_scan_mask 11 subset of 7. Never used
[    1.879197] max1363 1-0064: available_scan_mask 12 subset of 7. Never used
[    1.886084] max1363 1-0064: available_scan_mask 13 subset of 7. Never used
[    1.892971] max1363 1-0064: available_scan_mask 9 subset of 8. Never used
[    1.899771] max1363 1-0064: available_scan_mask 10 subset of 8. Never used
[    1.906657] max1363 1-0064: available_scan_mask 11 subset of 8. Never used
[    1.913544] max1363 1-0064: available_scan_mask 12 subset of 8. Never used
[    1.920430] max1363 1-0064: available_scan_mask 13 subset of 8. Never used
[    1.927322] max1363 1-0064: available_scan_mask 10 subset of 9. Never used
[    1.934210] max1363 1-0064: available_scan_mask 11 subset of 9. Never used
[    1.941096] max1363 1-0064: available_scan_mask 12 subset of 9. Never used
[    1.947980] max1363 1-0064: available_scan_mask 13 subset of 9. Never used
[    1.954867] max1363 1-0064: available_scan_mask 11 subset of 10. Never used
[    1.961841] max1363 1-0064: available_scan_mask 12 subset of 10. Never used
[    1.968815] max1363 1-0064: available_scan_mask 13 subset of 10. Never used
[    1.975789] max1363 1-0064: available_scan_mask 12 subset of 11. Never used
[    1.982762] max1363 1-0064: available_scan_mask 13 subset of 11. Never used
[    1.989735] max1363 1-0064: available_scan_mask 13 subset of 12. Never used

What is the correct way to fix these warnings?

Thanks,

Fabio Estevam

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Jonathan Cameron]

On Wed, 23 Apr 2025 17:23:28 -0300
Fabio Estevam <festevam@gmail.com> wrote:

> Hi,
> 
> After upgrading the kernel from 6.1 to 6.12 (also tested with
> linux-next), I started seeing the following warnings on a board
> populated with a Maxim MAX11601 ADC:
> 
> [    1.554029] max1363 1-0064: available_scan_mask 8 subset of 0. Never used
> [    1.563627] max1363 1-0064: available_scan_mask 9 subset of 0. Never used
> [    1.570439] max1363 1-0064: available_scan_mask 10 subset of 0. Never used
> [    1.577328] max1363 1-0064: available_scan_mask 11 subset of 0. Never used
> [    1.584226] max1363 1-0064: available_scan_mask 12 subset of 0. Never used
> [    1.591119] max1363 1-0064: available_scan_mask 13 subset of 0. Never used
> [    1.598013] max1363 1-0064: available_scan_mask 8 subset of 1. Never used
> [    1.604817] max1363 1-0064: available_scan_mask 9 subset of 1. Never used
> [    1.611623] max1363 1-0064: available_scan_mask 10 subset of 1. Never used
> [    1.618516] max1363 1-0064: available_scan_mask 11 subset of 1. Never used
> [    1.625403] max1363 1-0064: available_scan_mask 12 subset of 1. Never used
> [    1.632293] max1363 1-0064: available_scan_mask 13 subset of 1. Never used
> [    1.639201] max1363 1-0064: available_scan_mask 8 subset of 2. Never used
> [    1.646002] max1363 1-0064: available_scan_mask 9 subset of 2. Never used
> [    1.652802] max1363 1-0064: available_scan_mask 10 subset of 2. Never used
> [    1.659691] max1363 1-0064: available_scan_mask 11 subset of 2. Never used
> [    1.666582] max1363 1-0064: available_scan_mask 12 subset of 2. Never used
> [    1.673478] max1363 1-0064: available_scan_mask 13 subset of 2. Never used
> [    1.680382] max1363 1-0064: available_scan_mask 8 subset of 3. Never used
> [    1.687183] max1363 1-0064: available_scan_mask 9 subset of 3. Never used
> [    1.693984] max1363 1-0064: available_scan_mask 10 subset of 3. Never used
> [    1.700871] max1363 1-0064: available_scan_mask 11 subset of 3. Never used
> [    1.707758] max1363 1-0064: available_scan_mask 12 subset of 3. Never used
> [    1.714645] max1363 1-0064: available_scan_mask 13 subset of 3. Never used
> [    1.721532] max1363 1-0064: available_scan_mask 8 subset of 4. Never used
> [    1.728332] max1363 1-0064: available_scan_mask 9 subset of 4. Never used
> [    1.735134] max1363 1-0064: available_scan_mask 10 subset of 4. Never used
> [    1.742022] max1363 1-0064: available_scan_mask 11 subset of 4. Never used
> [    1.748908] max1363 1-0064: available_scan_mask 12 subset of 4. Never used
> [    1.755796] max1363 1-0064: available_scan_mask 13 subset of 4. Never used
> [    1.762683] max1363 1-0064: available_scan_mask 8 subset of 5. Never used
> [    1.769484] max1363 1-0064: available_scan_mask 9 subset of 5. Never used
> [    1.776283] max1363 1-0064: available_scan_mask 10 subset of 5. Never used
> [    1.783171] max1363 1-0064: available_scan_mask 11 subset of 5. Never used
> [    1.790065] max1363 1-0064: available_scan_mask 12 subset of 5. Never used
> [    1.796955] max1363 1-0064: available_scan_mask 13 subset of 5. Never used
> [    1.803846] max1363 1-0064: available_scan_mask 7 subset of 6. Never used
> [    1.810646] max1363 1-0064: available_scan_mask 8 subset of 6. Never used
> [    1.817446] max1363 1-0064: available_scan_mask 9 subset of 6. Never used
> [    1.824246] max1363 1-0064: available_scan_mask 10 subset of 6. Never used
> [    1.831164] max1363 1-0064: available_scan_mask 11 subset of 6. Never used
> [    1.838053] max1363 1-0064: available_scan_mask 12 subset of 6. Never used
> [    1.844941] max1363 1-0064: available_scan_mask 13 subset of 6. Never used
> [    1.851828] max1363 1-0064: available_scan_mask 8 subset of 7. Never used
> [    1.858627] max1363 1-0064: available_scan_mask 9 subset of 7. Never used
> [    1.865424] max1363 1-0064: available_scan_mask 10 subset of 7. Never used
> [    1.872311] max1363 1-0064: available_scan_mask 11 subset of 7. Never used
> [    1.879197] max1363 1-0064: available_scan_mask 12 subset of 7. Never used
> [    1.886084] max1363 1-0064: available_scan_mask 13 subset of 7. Never used
> [    1.892971] max1363 1-0064: available_scan_mask 9 subset of 8. Never used
> [    1.899771] max1363 1-0064: available_scan_mask 10 subset of 8. Never used
> [    1.906657] max1363 1-0064: available_scan_mask 11 subset of 8. Never used
> [    1.913544] max1363 1-0064: available_scan_mask 12 subset of 8. Never used
> [    1.920430] max1363 1-0064: available_scan_mask 13 subset of 8. Never used
> [    1.927322] max1363 1-0064: available_scan_mask 10 subset of 9. Never used
> [    1.934210] max1363 1-0064: available_scan_mask 11 subset of 9. Never used
> [    1.941096] max1363 1-0064: available_scan_mask 12 subset of 9. Never used
> [    1.947980] max1363 1-0064: available_scan_mask 13 subset of 9. Never used
> [    1.954867] max1363 1-0064: available_scan_mask 11 subset of 10. Never used
> [    1.961841] max1363 1-0064: available_scan_mask 12 subset of 10. Never used
> [    1.968815] max1363 1-0064: available_scan_mask 13 subset of 10. Never used
> [    1.975789] max1363 1-0064: available_scan_mask 12 subset of 11. Never used
> [    1.982762] max1363 1-0064: available_scan_mask 13 subset of 11. Never used
> [    1.989735] max1363 1-0064: available_scan_mask 13 subset of 12. Never used
> 
> What is the correct way to fix these warnings?

Ah.  I think we have an order of modes bug.. Later entries should never be a subset
of earlier ones and we only recently added a sanity check on that.

static const enum max1363_modes max11607_mode_list[] = {
	_s0, _s1, _s2, _s3,
	s0to1, s0to2, s0to3,
	s2to3,
	d0m1, d2m3, d1m0, d3m2,
	d0m1to2m3, d1m0to3m2,
};

Is used to build available_scan_masks for this device.
I'm failing to correlate with the warnings but clearly s2to3 is a subset of s0to3
channels 2,3 vs 0,1,2,3

In general we should do a few things in here.

Reorder the enum max1363 to reflect the subset rule correctly (may be
fine from a quick look).
Use that to set the entries in the max1363_mode_table.
(I think it's fine today but we can enforce that).

Finally ensure we obey the rules for the individual mode_list tables.

With that stuff fixed we should remove possibility of enabling more
channels than strictly necessary (which is what that print is moaning about.)

As a trivial test, just reorder max11607_mode_list[] it might fix your warning.
I'm a bit unconvinced that this is the only issue though as we should have
only seen 7 is a subset of 6.

If you can dump the available_modes table that is generated that might let
us see what is causing there to be so many warnings.

Jonathan





  
> 
> Thanks,
> 
> Fabio Estevam

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

Hi Jonathan,

On Sat, Apr 26, 2025 at 12:00 PM Jonathan Cameron <jic23@kernel.org> wrote:

> As a trivial test, just reorder max11607_mode_list[] it might fix your warning.

I appreciate your suggestion.

If I rearrange it like this (only added single channel entries), I
don't see any warnings:

static const enum max1363_modes max11607_mode_list[] = {
_s0, _s1, _s2, _s3,
s0to1, s2to3,
s0to2,
s0to3,
};

However, whenever the differential channels' definitions are inserted,
the warnings reappear.

> If you can dump the available_modes table that is generated that might let
> us see what is causing there to be so many warnings.

What is an appropriate place to dump the available_modes table?

I am happy to test any debug patches if you could share them.

Thanks,

Fabio Estevam

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Jonathan Cameron]

On Sat, 26 Apr 2025 18:00:07 -0300
Fabio Estevam <festevam@gmail.com> wrote:

> Hi Jonathan,
> 
> On Sat, Apr 26, 2025 at 12:00 PM Jonathan Cameron <jic23@kernel.org> wrote:
> 
> > As a trivial test, just reorder max11607_mode_list[] it might fix your warning.  
> 
> I appreciate your suggestion.
> 
> If I rearrange it like this (only added single channel entries), I
> don't see any warnings:
> 
> static const enum max1363_modes max11607_mode_list[] = {
> _s0, _s1, _s2, _s3,
> s0to1, s2to3,
> s0to2,
> s0to3,
> };
> 
> However, whenever the differential channels' definitions are inserted,
> the warnings reappear.
> 
> > If you can dump the available_modes table that is generated that might let
> > us see what is causing there to be so many warnings.  
> 
> What is an appropriate place to dump the available_modes table?

https://elixir.bootlin.com/linux/v6.14.4/source/drivers/iio/adc/max1363.c#L1460
There is where they are set.  Should show us if something weird is going on with
what the checks are seeing vs something going wrong at the debug check.

J

> 
> I am happy to test any debug patches if you could share them.
> 
> Thanks,
> 
> Fabio Estevam

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Matti Vaittinen]

Hi deee Ho peeps!

On 26/04/2025 18:00, Jonathan Cameron wrote:
> On Wed, 23 Apr 2025 17:23:28 -0300
> Fabio Estevam <festevam@gmail.com> wrote:
>> After upgrading the kernel from 6.1 to 6.12 (also tested with
>> linux-next), I started seeing the following warnings on a board
>> populated with a Maxim MAX11601 ADC:
>>
>> [    1.554029] max1363 1-0064: available_scan_mask 8 subset of 0. Never used
>> [    1.563627] max1363 1-0064: available_scan_mask 9 subset of 0. Never used
>>
>> What is the correct way to fix these warnings?
> 
> Ah.  I think we have an order of modes bug.. Later entries should never be a subset
> of earlier ones and we only recently added a sanity check on that.

This indeed rings a bell :) I have nothing really to add to the answers 
by Jonathan, but I just noticed the warning print isn't as clear as it 
could. As far as I understand, the printed values aren't the actual 
masks, but indexes in the mask arrays. Now that I had this stuff 
forgotten, I was puzzled by the print until I read the code.

I believe it'd be more informative if we printed the actual bit masks - 
but I am not sure if we know the size of the mask. If we keep printing 
the indexes, then we might want to add brackets [] to indicate the value 
is an index? How about:

"available_scan_masks: mask[8] subset of mask[0]. Never used"

instead of:
available_scan_mask 8 subset of 0. Never used

Would that be more obvious?

Yours,
	-- Matti

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

Hi Jonathan,

On Sun, Apr 27, 2025 at 7:23 AM Jonathan Cameron <jic23@kernel.org> wrote:

> https://elixir.bootlin.com/linux/v6.14.4/source/drivers/iio/adc/max1363.c#L1460
> There is where they are set.  Should show us if something weird is going on with
> what the checks are seeing vs something going wrong at the debug check.

I am not sure if this is what you want me to print:

--- a/drivers/iio/adc/max1363.c
+++ b/drivers/iio/adc/max1363.c
@@ -1453,6 +1453,8 @@ static int max1363_alloc_scan_masks(struct
iio_dev *indio_dev)

        indio_dev->available_scan_masks = masks;

+       pr_err("************ available_scan_masks is %lu\n", *masks);
+
        return 0;
 }

[    1.559919] ************ available_scan_masks is 1
[    1.565265] max1363 1-0064: available_scan_mask 8 subset of 0. Never used
[    1.572104] max1363 1-0064: available_scan_mask 9 subset of 0. Never used
[    1.578912] max1363 1-0064: available_scan_mask 10 subset of 0. Never used
[    1.585805] max1363 1-0064: available_scan_mask 11 subset of 0. Never used
[    1.592699] max1363 1-0064: available_scan_mask 12 subset of 0. Never used
[    1.599586] max1363 1-0064: available_scan_mask 13 subset of 0. Never used
[    1.606488] max1363 1-0064: available_scan_mask 8 subset of 1. Never used
[    1.613287] max1363 1-0064: available_scan_mask 9 subset of 1. Never used
[    1.620092] max1363 1-0064: available_scan_mask 10 subset of 1. Never used
[    1.626989] max1363 1-0064: available_scan_mask 11 subset of 1. Never used
[    1.633882] max1363 1-0064: available_scan_mask 12 subset of 1. Never used
[    1.640772] max1363 1-0064: available_scan_mask 13 subset of 1. Never used
[    1.647664] max1363 1-0064: available_scan_mask 8 subset of 2. Never used
[    1.654473] max1363 1-0064: available_scan_mask 9 subset of 2. Never used
[    1.661274] max1363 1-0064: available_scan_mask 10 subset of 2. Never used
[    1.668171] max1363 1-0064: available_scan_mask 11 subset of 2. Never used
[    1.675063] max1363 1-0064: available_scan_mask 12 subset of 2. Never used
[    1.681957] max1363 1-0064: available_scan_mask 13 subset of 2. Never used
[    1.688851] max1363 1-0064: available_scan_mask 8 subset of 3. Never used
[    1.695665] max1363 1-0064: available_scan_mask 9 subset of 3. Never used
[    1.702466] max1363 1-0064: available_scan_mask 10 subset of 3. Never used
[    1.709364] max1363 1-0064: available_scan_mask 11 subset of 3. Never used
[    1.716248] max1363 1-0064: available_scan_mask 12 subset of 3. Never used
[    1.723134] max1363 1-0064: available_scan_mask 13 subset of 3. Never used
[    1.730020] max1363 1-0064: available_scan_mask 8 subset of 4. Never used
[    1.736821] max1363 1-0064: available_scan_mask 9 subset of 4. Never used
[    1.743622] max1363 1-0064: available_scan_mask 10 subset of 4. Never used
[    1.750508] max1363 1-0064: available_scan_mask 11 subset of 4. Never used
[    1.757396] max1363 1-0064: available_scan_mask 12 subset of 4. Never used
[    1.764283] max1363 1-0064: available_scan_mask 13 subset of 4. Never used
[    1.771170] max1363 1-0064: available_scan_mask 8 subset of 5. Never used
[    1.777975] max1363 1-0064: available_scan_mask 9 subset of 5. Never used
[    1.784775] max1363 1-0064: available_scan_mask 10 subset of 5. Never used
[    1.791662] max1363 1-0064: available_scan_mask 11 subset of 5. Never used
[    1.798547] max1363 1-0064: available_scan_mask 12 subset of 5. Never used
[    1.805434] max1363 1-0064: available_scan_mask 13 subset of 5. Never used
[    1.812323] max1363 1-0064: available_scan_mask 7 subset of 6. Never used
[    1.819122] max1363 1-0064: available_scan_mask 8 subset of 6. Never used
[    1.825949] max1363 1-0064: available_scan_mask 9 subset of 6. Never used
[    1.832750] max1363 1-0064: available_scan_mask 10 subset of 6. Never used
[    1.839656] max1363 1-0064: available_scan_mask 11 subset of 6. Never used
[    1.846545] max1363 1-0064: available_scan_mask 12 subset of 6. Never used
[    1.853430] max1363 1-0064: available_scan_mask 13 subset of 6. Never used
[    1.860317] max1363 1-0064: available_scan_mask 8 subset of 7. Never used
[    1.867116] max1363 1-0064: available_scan_mask 9 subset of 7. Never used
[    1.873915] max1363 1-0064: available_scan_mask 10 subset of 7. Never used
[    1.880801] max1363 1-0064: available_scan_mask 11 subset of 7. Never used
[    1.887686] max1363 1-0064: available_scan_mask 12 subset of 7. Never used
[    1.894573] max1363 1-0064: available_scan_mask 13 subset of 7. Never used
[    1.901466] max1363 1-0064: available_scan_mask 9 subset of 8. Never used
[    1.908267] max1363 1-0064: available_scan_mask 10 subset of 8. Never used
[    1.915153] max1363 1-0064: available_scan_mask 11 subset of 8. Never used
[    1.922037] max1363 1-0064: available_scan_mask 12 subset of 8. Never used
[    1.928923] max1363 1-0064: available_scan_mask 13 subset of 8. Never used
[    1.935810] max1363 1-0064: available_scan_mask 10 subset of 9. Never used
[    1.942696] max1363 1-0064: available_scan_mask 11 subset of 9. Never used
[    1.949582] max1363 1-0064: available_scan_mask 12 subset of 9. Never used
[    1.956469] max1363 1-0064: available_scan_mask 13 subset of 9. Never used
[    1.963356] max1363 1-0064: available_scan_mask 11 subset of 10. Never used
[    1.970330] max1363 1-0064: available_scan_mask 12 subset of 10. Never used
[    1.977303] max1363 1-0064: available_scan_mask 13 subset of 10. Never used
[    1.984276] max1363 1-0064: available_scan_mask 12 subset of 11. Never used
[    1.991249] max1363 1-0064: available_scan_mask 13 subset of 11. Never used
[    1.998222] max1363 1-0064: available_scan_mask 13 subset of 12. Never used

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

Hi Matti,

On Mon, Apr 28, 2025 at 2:38 AM Matti Vaittinen
<mazziesaccount@gmail.com> wrote:

> I believe it'd be more informative if we printed the actual bit masks -
> but I am not sure if we know the size of the mask. If we keep printing
> the indexes, then we might want to add brackets [] to indicate the value
> is an index? How about:
>
> "available_scan_masks: mask[8] subset of mask[0]. Never used"
>
> instead of:
> available_scan_mask 8 subset of 0. Never used
>
> Would that be more obvious?

I still find the "Never used" part a bit cryptic. What exactly is never used?

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

On Mon, Apr 28, 2025 at 4:03 PM Fabio Estevam <festevam@gmail.com> wrote:
>
> Hi Jonathan,
>
> On Sun, Apr 27, 2025 at 7:23 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> > https://elixir.bootlin.com/linux/v6.14.4/source/drivers/iio/adc/max1363.c#L1460
> > There is where they are set.  Should show us if something weird is going on with
> > what the checks are seeing vs something going wrong at the debug check.
>
> I am not sure if this is what you want me to print:

Sorry, I should do it like this instead:

--- a/drivers/iio/adc/max1363.c
+++ b/drivers/iio/adc/max1363.c
@@ -1453,6 +1453,9 @@ static int max1363_alloc_scan_masks(struct
iio_dev *indio_dev)

        indio_dev->available_scan_masks = masks;

+       for (i = 0; i < st->chip_info->num_modes; i++)
+               pr_err("************ available_scan_masks is %lu\n", masks[i]);
+
        return 0;
 }

which prints:

[    1.567841] ************ available_scan_masks is 1
[    1.577203] ************ available_scan_masks is 2
[    1.582032] ************ available_scan_masks is 4
[    1.586837] ************ available_scan_masks is 8
[    1.591644] ************ available_scan_masks is 3
[    1.596452] ************ available_scan_masks is 7
[    1.601258] ************ available_scan_masks is 15
[    1.606149] ************ available_scan_masks is 12
[    1.611041] ************ available_scan_masks is 4096
[    1.616101] ************ available_scan_masks is 8192
[    1.616105] ************ available_scan_masks is 262144
[    1.616108] ************ available_scan_masks is 524288
[    1.640493] ************ available_scan_masks is 12288
[    1.645640] ************ available_scan_masks is 786432
[    1.652223] max1363 1-0064: available_scan_mask 8 subset of 0. Never used
[    1.659028] max1363 1-0064: available_scan_mask 9 subset of 0. Never used
[    1.665829] max1363 1-0064: available_scan_mask 10 subset of 0. Never used
[    1.672722] max1363 1-0064: available_scan_mask 11 subset of 0. Never used
[    1.677071] fec 30be0000.ethernet eth0: registered PHC device 0
[    1.679623] max1363 1-0064: available_scan_mask 12 subset of 0. Never used
[    1.679630] max1363 1-0064: available_scan_mask 13 subset of 0. Never used
[    1.699327] max1363 1-0064: available_scan_mask 8 subset of 1. Never used
[    1.706131] max1363 1-0064: available_scan_mask 9 subset of 1. Never used
[    1.712932] max1363 1-0064: available_scan_mask 10 subset of 1. Never used
[    1.719819] max1363 1-0064: available_scan_mask 11 subset of 1. Never used
[    1.726706] max1363 1-0064: available_scan_mask 12 subset of 1. Never used
[    1.733593] max1363 1-0064: available_scan_mask 13 subset of 1. Never used
[    1.740490] max1363 1-0064: available_scan_mask 8 subset of 2. Never used
[    1.747296] max1363 1-0064: available_scan_mask 9 subset of 2. Never used
[    1.754106] max1363 1-0064: available_scan_mask 10 subset of 2. Never used
[    1.760995] max1363 1-0064: available_scan_mask 11 subset of 2. Never used
[    1.767882] max1363 1-0064: available_scan_mask 12 subset of 2. Never used
[    1.774769] max1363 1-0064: available_scan_mask 13 subset of 2. Never used
[    1.781660] max1363 1-0064: available_scan_mask 8 subset of 3. Never used
[    1.788470] max1363 1-0064: available_scan_mask 9 subset of 3. Never used
[    1.795280] max1363 1-0064: available_scan_mask 10 subset of 3. Never used
[    1.802170] max1363 1-0064: available_scan_mask 11 subset of 3. Never used
[    1.809058] max1363 1-0064: available_scan_mask 12 subset of 3. Never used
[    1.815947] max1363 1-0064: available_scan_mask 13 subset of 3. Never used
[    1.822836] max1363 1-0064: available_scan_mask 8 subset of 4. Never used
[    1.829658] max1363 1-0064: available_scan_mask 9 subset of 4. Never used
[    1.836465] max1363 1-0064: available_scan_mask 10 subset of 4. Never used
[    1.843356] max1363 1-0064: available_scan_mask 11 subset of 4. Never used
[    1.850273] max1363 1-0064: available_scan_mask 12 subset of 4. Never used
[    1.857191] max1363 1-0064: available_scan_mask 13 subset of 4. Never used
[    1.864101] max1363 1-0064: available_scan_mask 8 subset of 5. Never used
[    1.870913] max1363 1-0064: available_scan_mask 9 subset of 5. Never used
[    1.874462] mv88e6085 30be0000.ethernet-1:00: switch 0x1150
detected: Marvell 88E6320, revision 2
[    1.877716] max1363 1-0064: available_scan_mask 10 subset of 5. Never used
[    1.893466] max1363 1-0064: available_scan_mask 11 subset of 5. Never used
[    1.900355] max1363 1-0064: available_scan_mask 12 subset of 5. Never used
[    1.907250] max1363 1-0064: available_scan_mask 13 subset of 5. Never used
[    1.914139] max1363 1-0064: available_scan_mask 7 subset of 6. Never used
[    1.920938] max1363 1-0064: available_scan_mask 8 subset of 6. Never used
[    1.927747] max1363 1-0064: available_scan_mask 9 subset of 6. Never used
[    1.934560] max1363 1-0064: available_scan_mask 10 subset of 6. Never used
[    1.941453] max1363 1-0064: available_scan_mask 11 subset of 6. Never used
[    1.948340] max1363 1-0064: available_scan_mask 12 subset of 6. Never used
[    1.955225] max1363 1-0064: available_scan_mask 13 subset of 6. Never used
[    1.962111] max1363 1-0064: available_scan_mask 8 subset of 7. Never used
[    1.968912] max1363 1-0064: available_scan_mask 9 subset of 7. Never used
[    1.975718] max1363 1-0064: available_scan_mask 10 subset of 7. Never used
[    1.982613] max1363 1-0064: available_scan_mask 11 subset of 7. Never used
[    1.989502] max1363 1-0064: available_scan_mask 12 subset of 7. Never used
[    1.996389] max1363 1-0064: available_scan_mask 13 subset of 7. Never used
[    2.003282] max1363 1-0064: available_scan_mask 9 subset of 8. Never used
[    2.010084] max1363 1-0064: available_scan_mask 10 subset of 8. Never used
[    2.016970] max1363 1-0064: available_scan_mask 11 subset of 8. Never used
[    2.023855] max1363 1-0064: available_scan_mask 12 subset of 8. Never used
[    2.030742] max1363 1-0064: available_scan_mask 13 subset of 8. Never used
[    2.037626] max1363 1-0064: available_scan_mask 10 subset of 9. Never used
[    2.044514] max1363 1-0064: available_scan_mask 11 subset of 9. Never used
[    2.051400] max1363 1-0064: available_scan_mask 12 subset of 9. Never used
[    2.058287] max1363 1-0064: available_scan_mask 13 subset of 9. Never used
[    2.065175] max1363 1-0064: available_scan_mask 11 subset of 10. Never used
[    2.072149] max1363 1-0064: available_scan_mask 12 subset of 10. Never used
[    2.079122] max1363 1-0064: available_scan_mask 13 subset of 10. Never used
[    2.086101] max1363 1-0064: available_scan_mask 12 subset of 11. Never used
[    2.093077] max1363 1-0064: available_scan_mask 13 subset of 11. Never used
[    2.100055] max1363 1-0064: available_scan_mask 13 subset of 12. Never used

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Matti Vaittinen]

On 28/04/2025 22:04, Fabio Estevam wrote:
> Hi Matti,
> 
> On Mon, Apr 28, 2025 at 2:38 AM Matti Vaittinen
> <mazziesaccount@gmail.com> wrote:
> 
>> I believe it'd be more informative if we printed the actual bit masks -
>> but I am not sure if we know the size of the mask. If we keep printing
>> the indexes, then we might want to add brackets [] to indicate the value
>> is an index? How about:
>>
>> "available_scan_masks: mask[8] subset of mask[0]. Never used"
>>
>> instead of:
>> available_scan_mask 8 subset of 0. Never used
>>
>> Would that be more obvious?
> 
> I still find the "Never used" part a bit cryptic. What exactly is never used?

When user wants to enable some channels, the IIO core scans the 
available_scan_masks -array in order to find a supported configuration 
which meets the requirements. IIO core does this scanning in the order, 
and stops when first suitable mask is found from the available_scan_masks.

This means that if we have a mask which is a subset of a mask which is 
earlier in the array, this latter mask will never be used because the 
earlier one (the superset) will always be found first and picked by the 
IIO core.

Eg, if mask[0] consists of bits
0,3,5,7

and mask[1] consists of bits
0,5

- then if user wants to enable channels 0 or 5 (or 0 and 5) - the 
mask[0] will always be picked by the IIO core because it fulfills the 
needs. This means IIO will always enable channels 0,3,5 and 7 - and 
never use the smaller configuration of only channels 0 and 5.

Hence, the ordering of the masks matters, and this check (and print) was 
added.

I hope this clarifies.

Yours,
	-- Matti

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Matti Vaittinen]

On 29/04/2025 00:16, Fabio Estevam wrote:
> On Mon, Apr 28, 2025 at 4:03 PM Fabio Estevam <festevam@gmail.com> wrote:
>>
>> Hi Jonathan,
>>
>> On Sun, Apr 27, 2025 at 7:23 AM Jonathan Cameron <jic23@kernel.org> wrote:
>>
>>> https://elixir.bootlin.com/linux/v6.14.4/source/drivers/iio/adc/max1363.c#L1460
>>> There is where they are set.  Should show us if something weird is going on with
>>> what the checks are seeing vs something going wrong at the debug check.
>>
>> I am not sure if this is what you want me to print:
> 
> Sorry, I should do it like this instead:
> 
> --- a/drivers/iio/adc/max1363.c
> +++ b/drivers/iio/adc/max1363.c
> @@ -1453,6 +1453,9 @@ static int max1363_alloc_scan_masks(struct
> iio_dev *indio_dev)
> 
>          indio_dev->available_scan_masks = masks;
> 
> +       for (i = 0; i < st->chip_info->num_modes; i++)
> +               pr_err("************ available_scan_masks is %lu\n", masks[i]);
> +
>          return 0;
>   }
> 
> which prints:
> 
> [    1.567841] ************ available_scan_masks is 1
> [    1.577203] ************ available_scan_masks is 2
> [    1.582032] ************ available_scan_masks is 4
> [    1.586837] ************ available_scan_masks is 8
> [    1.591644] ************ available_scan_masks is 3
> [    1.596452] ************ available_scan_masks is 7
> [    1.601258] ************ available_scan_masks is 15
> [    1.606149] ************ available_scan_masks is 12

Here, 12 is subset of 15.

> [    1.611041] ************ available_scan_masks is 4096
> [    1.616101] ************ available_scan_masks is 8192
> [    1.616105] ************ available_scan_masks is 262144
> [    1.616108] ************ available_scan_masks is 524288
> [    1.640493] ************ available_scan_masks is 12288
> [    1.645640] ************ available_scan_masks is 786432
> [    1.652223] max1363 1-0064: available_scan_mask 8 subset of 0. Never used
> [    1.659028] max1363 1-0064: available_scan_mask 9 subset of 0. Never used
> [    1.665829] max1363 1-0064: available_scan_mask 10 subset of 0. Never used
> [    1.672722] max1363 1-0064: available_scan_mask 11 subset of 0. Never used

// snip

So, majority of these prints seem to be garbage. AFAICS, we should only see:
 > [    1.652223] max1363 1-0064: available_scan_mask 8 subset of 7. 
Never used

Or maybe:
available_scan_mask: mask[8] subset of mask[7]. Never used

Do you think you could send a patch to fix this, or should I take a look 
at it?

Yours,
	-- Matti

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

Hi Matti,

On Tue, Apr 29, 2025 at 12:59 AM Matti Vaittinen
<mazziesaccount@gmail.com> wrote:

> So, majority of these prints seem to be garbage. AFAICS, we should only see:
>  > [    1.652223] max1363 1-0064: available_scan_mask 8 subset of 7.
> Never used
>
> Or maybe:
> available_scan_mask: mask[8] subset of mask[7]. Never used
>
> Do you think you could send a patch to fix this, or should I take a look
> at it?

Please take a look at it if you have a chance. I will be glad to test a patch.

Thanks!

Re: max1363 : Warnings from iio_sanity_check_avail_scan_masks()

[Fabio Estevam]

Hi Matti,

On Tue, Apr 29, 2025 at 12:59 AM Matti Vaittinen
<mazziesaccount@gmail.com> wrote:

> Do you think you could send a patch to fix this, or should I take a look
> at it?

Yes, I think I understand the problem better now and will send the patches.

Thanks for your help.