Re: RE: [PATCH net-next 07/13] net: fec: fec_probe(): update quirk: bring IRQs in correct order

[Marc Kleine-Budde]

On 17.10.2024 03:09:15, Wei Fang wrote:
> > -----Original Message-----
> > From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> > Sent: 2024年10月17日 5:52
> > To: Wei Fang <wei.fang@xxxxxxx>; Shenwei Wang <shenwei.wang@xxxxxxx>;
> > Clark Wang <xiaoning.wang@xxxxxxx>; David S. Miller
> > <davem@xxxxxxxxxxxxx>; Eric Dumazet <edumazet@xxxxxxxxxx>; Jakub
> > Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni <pabeni@xxxxxxxxxx>; Richard
> > Cochran <richardcochran@xxxxxxxxx>
> > Cc: imx@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > kernel@xxxxxxxxxxxxxx; Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> > Subject: [PATCH net-next 07/13] net: fec: fec_probe(): update quirk: bring IRQs
> > in correct order
> > 
> > With i.MX8MQ and compatible SoCs, the order of the IRQs in the device
> > tree is not optimal. The driver expects the first three IRQs to match
> > their corresponding queue, while the last (fourth) IRQ is used for the
> > PPS:
> > 
> > - 1st IRQ: "int0": queue0 + other IRQs
> > - 2nd IRQ: "int1": queue1
> > - 3rd IRQ: "int2": queue2
> > - 4th IRQ: "pps": pps
> > 
> > However, the i.MX8MQ and compatible SoCs do not use the
> > "interrupt-names" property and specify the IRQs in the wrong order:
> > 
> > - 1st IRQ: queue1
> > - 2nd IRQ: queue2
> > - 3rd IRQ: queue0 + other IRQs
> > - 4th IRQ: pps
> > 
> > First rename the quirk from FEC_QUIRK_WAKEUP_FROM_INT2 to
> > FEC_QUIRK_INT2_IS_MAIN_IRQ, to better reflect it's functionality.
> > 
> > If the FEC_QUIRK_INT2_IS_MAIN_IRQ quirk is active, put the IRQs back
> > in the correct order, this is done in fec_probe().
> > 
> 
> I think FEC_QUIRK_INT2_IS_MAIN_IRQ or FEC_QUIRK_WAKEUP_FROM_INT2
> is *NO* needed anymore. Actually, INT2 is also the main IRQ for i.MX8QM and
> its compatible SoCs, but i.MX8QM uses a different solution. I don't know why
> there are two different ways of doing it, as I don't know the history. But you can
> refer to the solution of i.MX8QM, which I think is more suitable.
> 
> See arch/arm64/boot/dts/freescale/imx8-ss-conn.dtsi, the IRQ 258 is
> placed first.

Yes, that is IMHO the correct description of the IP core, but the
i.MX8M/N/Q DTS have the wrong order of IRQs. And for compatibility
reasons (fixed DTS with old driver) it's IMHO not possible to change the
DTS.

> fec1: ethernet@5b040000 {
> 		reg = <0x5b040000 0x10000>;
> 		interrupts = <GIC_SPI 258 IRQ_TYPE_LEVEL_HIGH>,
> 			     <GIC_SPI 256 IRQ_TYPE_LEVEL_HIGH>,
> 			     <GIC_SPI 257 IRQ_TYPE_LEVEL_HIGH>,
> 			     <GIC_SPI 259 IRQ_TYPE_LEVEL_HIGH>;

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
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