[PATCH v5 4/4] ARM: dts: stm32: add initial support for stm32mp157-ultra-fly-sbc board

[Andrew Lunn]

On Thu, May 08, 2025 at 03:10:09PM +0200, Goran Radenovic wrote:
> Hi Andrew,
> 
> thank You once again for helpful hint.
> 
> Andrew Lunn wrote:
> > > > > +	phy-handle = <&phy1>;
> > > > > +
> > > > > +	mdio {
> > > > > +		#address-cells = <1>;
> > > > > +		#size-cells = <0>;
> > > > > +		compatible = "snps,dwmac-mdio";
> > > > > +		phy1: ethernet-phy at 1 {
> > > > > +			reg = <1>;
> > > > > +			interrupt-parent = <&gpiod>;
> > > > > +			interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
> > > > PHY interrupts are 99% time level, not edge.
> > > That is correct, but I am facing strange behavior, when I set
> > > IRQ_TYPE_LEVEL_LOW.
> > > My board stops booting at:
> > > 
> > > [    2.343233] Waiting for root device /dev/mmcblk0p4...
> > > [   12.638818] platform 5a006000.usbphyc: deferred probe pending
> > > [   12.643192] platform 49000000.usb-otg: deferred probe pending
> > > [   12.649029] platform 48003000.adc: deferred probe pending
> > > [   12.654277] platform 5800d000.usb: deferred probe pending
> > > [   12.659744] platform 5800c000.usb: deferred probe pending
> > > [   12.665089] amba 58005000.mmc: deferred probe pending
> > > [   12.670239] amba 58007000.mmc: deferred probe pending
> > > [   12.675185] platform 50025000.vrefbuf: deferred probe pending
> > > 
> > > I must investigate this. If You have any idea, You are welcome to share it.
> > Could be an interrupt storm. The interrupt is not getting cleared
> > because of something missing in the PHY driver, so it just fires again
> > and again.
> 
> After a brief investigation, I tend to agree with your assessment that the
> issue lies in the driver—likely the stmmac driver — which is outside the
> scope of my changes.
> 
> Therefore, I would suggest keeping IRQ_TYPE_EDGE_FALLING for now, or
> alternatively not using a hardware IRQ at all and falling back to polling,
> as done in stm32mp15xx-dkx.dtsi.

Since edge is wrong, please use polling.

	Andrew