[5200] ATA and (BAD) interrupts question

[5200] ATA and (BAD) interrupts question

[Albrecht Dreß]

Hi all,

I run linux 2.6.29.1 from kernel.org on a custom Freescale MPC5200B based b=
oard, which has a CF card attached to the 5200's ATA.  The CF seems to run =
nicely, but I am somewhat confused by the interrupts reproted by the kernel=
.

Immediately after the boot, /proc/interrupts reports (inter alia)

135:          8  MPC52xx Peripherals Edge      mpc52xx_ata
194:          0  MPC52xx SDMA Edge      ATA task
BAD:         44

Then I say 'mount -t vfat -o noatime /dev/sda1 /mnt/cf0', and I get

135:         41  MPC52xx Peripherals Edge      mpc52xx_ata
194:          0  MPC52xx SDMA Edge      ATA task
BAD:         44

Then, I recursively copy a folder to the CF card:

135:     125111  MPC52xx Peripherals Edge      mpc52xx_ata
194:          0  MPC52xx SDMA Edge      ATA task
BAD:     121863

Is it correct that the "ATA task" interrupts are still 0, and that I get su=
ch a high number of BAD ones?  Is there a way to detect which source actual=
ly triggered the BAD interrupts?

Thanks in advance,
Albrecht.

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Re: [5200] ATA and (BAD) interrupts question

[Grant Likely]

On Tue, Jul 28, 2009 at 6:50 AM, Albrecht Dre=DF<albrecht.dress@arcor.de> w=
rote:
> Hi all,
>
> I run linux 2.6.29.1 from kernel.org on a custom Freescale MPC5200B based=
 board, which has a CF card attached to the 5200's ATA. =A0The CF seems to =
run nicely, but I am somewhat confused by the interrupts reproted by the ke=
rnel.
>
> Immediately after the boot, /proc/interrupts reports (inter alia)
>
> 135: =A0 =A0 =A0 =A0 =A08 =A0MPC52xx Peripherals Edge =A0 =A0 =A0mpc52xx_=
ata
> 194: =A0 =A0 =A0 =A0 =A00 =A0MPC52xx SDMA Edge =A0 =A0 =A0ATA task
> BAD: =A0 =A0 =A0 =A0 44
>
> Then I say 'mount -t vfat -o noatime /dev/sda1 /mnt/cf0', and I get
>
> 135: =A0 =A0 =A0 =A0 41 =A0MPC52xx Peripherals Edge =A0 =A0 =A0mpc52xx_at=
a
> 194: =A0 =A0 =A0 =A0 =A00 =A0MPC52xx SDMA Edge =A0 =A0 =A0ATA task
> BAD: =A0 =A0 =A0 =A0 44
>
> Then, I recursively copy a folder to the CF card:
>
> 135: =A0 =A0 125111 =A0MPC52xx Peripherals Edge =A0 =A0 =A0mpc52xx_ata
> 194: =A0 =A0 =A0 =A0 =A00 =A0MPC52xx SDMA Edge =A0 =A0 =A0ATA task
> BAD: =A0 =A0 121863
>
> Is it correct that the "ATA task" interrupts are still 0, and that I get =
such a high number of BAD ones? =A0Is there a way to detect which source ac=
tually triggered the BAD interrupts?

No, not really, but I'd spend some time looking at the DMA portion of
the IRQ handler.  Either edge IRQs are not getting acked correctly, or
the interrupt controller driver is not reading the pending IRQs
correctly.

g.

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