Re: [PATCH] power: supply: bd71828: add input current limit property

[Matti Vaittinen]

On 15/04/2026 23:13, Andreas Kemnade wrote:
> On Tue, 7 Apr 2026 09:33:25 +0300
> Matti Vaittinen <mazziesaccount@xxxxxxxxx> wrote:
>
> > I am afraid I don't know your use-case for the control of the DCIN input
> > limit well enough to decide, if the BD72720 would need something similar
> > - or if the VBUS_INLIM should be tied to the same knob. If you have the
> > enthusiasm to write some more words ... I am keen on learning! :)
>
> Justification for this patch is mostly: there is a standard interface
> for this functionality and the chip has that functionality.

I wasn't doubting the justification for this patch. I was more like 
wondering if the use-case of the functionality, toggled by the 
interface, is such that BD72720 VBUS_INLIM should be tied to this same knob.

> The bigger picture: Attach a power source with changing properties causes
> mess. To repreduce issues at my desk, I have played around with a labor power
> supply with changeable current limitation, turining it down to zero (so
> power is off) then turning it on slowly again, no charging will happen. My
> usual way around such a problem is to clear DCIN_ILIM_EN (will add a sysfs
> attribute for that) and set some conservative current.

Right. I suppose deciding if the BD72720 should support changing the 
VBUS_INLIM would require me to have the hardware to do some testing so I 
could see how it behaves with variable charging currents. I don't 
currently have that, and I haven't heard of any complaints. Furthermore, 
AFAIR, there are some differences between the logic of BD71828 and 
BD72720 (battery assisted mode in BD72720) - so they're not 100% same. 
Hence, I won't touch the BD72720 for now.

Thanks for sharing the details!

Yours,
	-- Matti

--
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Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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