On 4/18/23 11:14, Patrice CHOTARD wrote:
Hi Marek
Hello Patrice,
On 4/18/23 10:25, Marek Vasut wrote:
On 4/18/23 09:21, Patrice CHOTARD wrote:
Hi Marek
Hello Patrice,
On 4/17/23 19:00, Marek Vasut wrote:
On 4/17/23 18:56, Patrice Chotard wrote:
In case USB hub regulator is shared, unexpected behavior occurs.
On stm32mp135f-dk, stm32mp157c-ev1 and stm32mp157x-dkx, regulator
v3v3 is shared between several IP/devices (USB, panel, ethernet phy,
camera, ...).
Running command "usb stop", v3v3 regulator is switched off and
the splashscreen content disappear.
v3v3 shouldn't be disabled on usb_onboard_hub_remove() callback.
Isn't the regulator enable/disable refcounted ?
There is no refcount on regulator that's why we let regulator enable.
Can we add that, instead of hacking around the missing refcount in every driver
?
I agree, it should a nice solution but, there is a but ;-)
_ it's the same situation for clocks and resets, there is no ref counter.
Those should indeed be fixed too. Hayashi-san from Socionext ran into
the same problem recently IIRC.
_ what about side effects by adding ref counter where some platforms does
several enable on the same regulator (or even clock or reset) and only one
disable on it thinking that it's off ? or introduce new
regulator_shared_xxx() API
to avoid side-effect with existing code.
Such platforms should be fixed if they misuse the regulators.
_ unfortunately, currently, i didn't get enough bandwidth to address these
points :-(.
I also don't want to perpetuate these workarounds, can you find someone
to add the refcounting ? It shouldn't be that hard, probably a new
regulator struct member and ++/-- in enable/disable , maybe with some
underflow check here and there.
