Hello Shawn,
On 19.01.21 09:57, Shawn Guo wrote:
> On Fri, Nov 13, 2020 at 04:28:55PM +0100, Ahmad Fatoum wrote:
>> The SoC dtsi lists a NOP USB PHY for each of the two HSIC-only USB
>> controllers. Their device tree node doesn't indicate a vcc-supply
>> resulting in:
>>
>> usb_phy_generic usbphynop1: supply vcc not found, using dummy regulator
>> usb_phy_generic usbphynop2: supply vcc not found, using dummy regulator
>
> So the patch is all for removing this kernel message, with introducing
> the following potential breakage?
Pretty much. Either:
- We never fix the warning
- We add an explicit dummy fixed-regulator, which doesn't reflect the HW
- We reference the correct regulator and have the low risk of a
non-upstream device tree breaking when they update both kernel,
device tree and have an non-recommended CONFIG_REGULATOR_ANATOP=n
What do you think?
Cheers,
Ahmad
>
> Shawn
>
>>
>> warnings on boot up. The USB IP vcc-supply - separate from the vusb - is
>> hardwired to LDO_2P5[1], which we already have a device tree node for.
>> Reference it for the dummy "phy" as well.
>>
>> This will lead to breakage (probe deferment) for kernels that:
>> - Use a HSIC USB controller
>> - Use this new device tree
>> - but have CONFIG_REGULATOR_ANATOP disabled
>>
>> Because while the regulator is always-on, it can't be resolved when
>> there is no driver for it.
>>
>> As there are
>>
>> - no affected upstream device trees
>> - existing device trees are unaffected without recompilation
>> - disabling CONFIG_REGULATOR_ANATOP is explicitly a non-recommended
>> configuration per symbol help text
>>
>> this potential breakage is deemed acceptable.
>>
>> [1]: i.MX 6Dual/6Quad Reference Manual, Rev. C,
>> Figure 53-1. Power System Overview
>>
>> Cc: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
>> ---
>> arch/arm/boot/dts/imx6qdl.dtsi | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
>> index 43edbf1156c7..22e4c142de13 100644
>> --- a/arch/arm/boot/dts/imx6qdl.dtsi
>> +++ b/arch/arm/boot/dts/imx6qdl.dtsi
>> @@ -131,11 +131,13 @@ pmu: pmu {
>>
>> usbphynop1: usbphynop1 {
>> compatible = "usb-nop-xceiv";
>> + vcc-supply = <®_vdd2p5>;
>> #phy-cells = <0>;
>> };
>>
>> usbphynop2: usbphynop2 {
>> compatible = "usb-nop-xceiv";
>> + vcc-supply = <®_vdd2p5>;
>> #phy-cells = <0>;
>> };
>>
>> --
>> 2.28.0
>>
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
