Hi Henk,

On Mon, Mar 8, 2010 at 8:20 AM, Henk Stegeman [off-list ref] wro=
te:

I'm trying to make use of the GPT as interrupt controller.
My driver is getting most, but not all of the interrupts, besides that
I'm getting a whole bunch of spurious IRQs, so I'm trying to figure
out what's wrong.

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0gpt6: timer@660 {
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible =3D "fsl,mpc520=

0b-gpt","fsl,mpc5200-gpt";

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0x660 0x10>;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts =3D <1 15 0>;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-controller;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0#interrupt-cells =3D <1>;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0};

My device has the interrupt-parent property which links it to the
above interrupt controller.

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0spi@f00 {
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0#address-cells =3D <1>;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0#size-cells =3D <0>;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible =3D "fsl,mpc520=

0b-spi","fsl,mpc5200-spi";

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0xf00 0x20>;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts =3D <2 13 0 2 1=

4 0>;

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0io-controller@0 {
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0compatible=

 =3D "microkey,smc4000io";

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0linux,moda=

lias =3D "of_smc4000io";

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0spi-max-fr=

equency =3D <800000>;

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0spi-cpha;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0reg =3D <0=
;
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0word-delay=

-us =3D <30>;

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupt-=

parent =3D <&gpt6>;

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0interrupts=

 =3D <2>; // And make it edge falling

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0};

There are two things I find suspicious:
- First of all my interrupt is listed as virq# 16, shouldn't it be
virq# 0x50 ? (16 is te L2 value virq# 0x50 of mpc52xx_irqhost_map)

The GPT irq registered as a different IRQ controller, so it will be
assigned an entirely different number within the virq range.

- Secondly in mpc52xx_gpt.c =A0mpc52xx_gpt_irq_mask() and
mpc52xx_gpt_irq_unmask() resp. clear and set the IrqEn bit of the GPT,
which is described in the MPC5200B_UM as "enables interrupt generation
to the CPU for all modes". The word 'generation' makes me suspicious,
because it could mean that while irqEn is cleared an edge on the GPT's
input does not even request an IRQ immediately after the bit is
cleared. =A0Or in other words, clearing the bit could do more that just
masking.

Could be, the IRQ support has not gotten extensive testing.  It may
require additional work.

~ # cat /proc/interrupts
=A0 =A0 =A0 =A0 =A0 CPU0
=A016: =A0 =A01338686 =A0 MPC52xx GPT =A0 =A0 =A0Edge =A0 =A0 =A0 =A0 smc=

4000io

129: =A0 =A0 =A083224 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0mpc52x=

x_psc_uart

130: =A0 =A0 =A0 =A0 =A01 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0mp=

c52xx_psc_uart

133: =A0 =A0 =A0 =A0 =A00 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0mp=

c52xx-fec_ctrl

134: =A0 =A0 =A0 =A0 =A00 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0oh=

ci_hcd:usb1

135: =A0 =A0 =A016127 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0mpc52x=

x_ata

141: =A0 =A0 =A0 =A0 =A00 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0mp=

c5200-spi-modf

142: =A0 =A0 =A079184 =A0 MPC52xx Peripherals Level =A0 =A0 =A0 =A0mpc520=

0-spi-spif

192: =A0 =A0 =A0 =A0 =A00 =A0 MPC52xx SDMA =A0 =A0 Level =A0 =A0 =A0 =A0A=

TA task

193: =A0 =A0 =A0 =A0 15 =A0 MPC52xx SDMA =A0 =A0 Level =A0 =A0 =A0 =A0mpc=

52xx-fec_rx

194: =A0 =A0 =A035615 =A0 MPC52xx SDMA =A0 =A0 Level =A0 =A0 =A0 =A0mpc52=

xx-fec_tx

LOC: =A0 =A0 134286 =A0 Local timer interrupts
SPU: =A0 =A0 576958 =A0 Spurious interrupts
CNT: =A0 =A0 =A0 =A0 =A00 =A0 Performance monitoring interrupts
MCE: =A0 =A0 =A0 =A0 =A00 =A0 Machine check exceptions

~ # dmesg |grep 660
[ =A0 =A01.975928] irq: irq 0 on host /soc5200@f0000000/timer@660 mapped
to virtual irq 16

~ # dmesg | grep host_map
[ =A0 =A00.000000] mpc52xx_irqhost_map: virq=3D81, l1=3D2, l2=3D1
[ =A0 =A00.319272] mpc52xx_irqhost_map: External IRQ1 virq=3D41, hw=3D41.=

 type=3D8

[ =A0 =A00.376117] mpc52xx_irqhost_map: virq=3D49, l1=3D1, l2=3D9
[ =A0 =A00.417213] mpc52xx_irqhost_map: virq=3D4a, l1=3D1, l2=3D10
[ =A0 =A00.452119] mpc52xx_irqhost_map: virq=3D4b, l1=3D1, l2=3D11
[ =A0 =A00.487031] mpc52xx_irqhost_map: virq=3D4c, l1=3D1, l2=3D12
[ =A0 =A00.529899] mpc52xx_irqhost_map: virq=3D4d, l1=3D1, l2=3D13
[ =A0 =A00.564821] mpc52xx_irqhost_map: virq=3D4e, l1=3D1, l2=3D14
[ =A0 =A00.599744] mpc52xx_irqhost_map: virq=3D4f, l1=3D1, l2=3D15
[ =A0 =A00.634669] mpc52xx_irqhost_map: virq=3D50, l1=3D1, l2=3D16
[ =A0 =A01.629764] mpc52xx_irqhost_map: virq=3D82, l1=3D2, l2=3D2
[ =A0 =A01.667194] mpc52xx_irqhost_map: virq=3D84, l1=3D2, l2=3D4
[ =A0 =A01.763299] mpc52xx_irqhost_map: virq=3D87, l1=3D2, l2=3D7
[ =A0 =A01.790510] mpc52xx_irqhost_map: virq=3Dc0, l1=3D3, l2=3D0
[ =A0 =A01.909341] mpc52xx_irqhost_map: virq=3D8d, l1=3D2, l2=3D13
[ =A0 =A01.936712] mpc52xx_irqhost_map: virq=3D8e, l1=3D2, l2=3D14
[ =A0 =A02.055579] mpc52xx_irqhost_map: virq=3Dc1, l1=3D3, l2=3D1
[ =A0 =A02.083018] mpc52xx_irqhost_map: virq=3Dc2, l1=3D3, l2=3D2
[ =A0 =A02.110345] mpc52xx_irqhost_map: virq=3D85, l1=3D2, l2=3D5
[ =A0 =A02.211890] mpc52xx_irqhost_map: virq=3D86, l1=3D2, l2=3D6

This grep only shows the output from mpc52xx_intc.c.  The GPT driver
has its own IRQ mapping function; mpc52xx_gpt_irq_map(), which is why
you're not seeing your IRQ map debug message.

Cheers,
g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.