Re: ata, pcmcia: problem with irq and ata_dev_read_id()

[Heiko Schocher <hs@denx.de>]

Hello Tejun,

Tejun Heo wrote:
> On 07/05/2010 10:26 AM, Heiko Schocher wrote:
>> IRQ 26: too many spurious IRQs, disabling and polling for 10k 10msec intervals.
>> IRQ 26: system performance may be affected
>> handlers:
>> [<c0198d00>] (ata_sff_interrupt+0x0/0x204)
> 
> Yeah, that's the new polling code kicking in.  If the IRQ problem
> doesn't persiste (which should be the case here), polling will step
> down after a while and everything will return to normal.  If you keep
> the system running more than ten minutes and use the CF device, does
> the kernel complain anymore?

No, I can use the CF while kernel is in polling mode, also if the
kernel switched back to irq mode:

Log, direct after kernel is up:

[...]
Freeing unused kernel memory: 132k init
-bash-3.2# mount -t vfat /dev/sdb1 /home/hs/mnt
-bash-3.2# cat /proc/uptime
62.08 14.08
-bash-3.2# cat /proc/interrupts
           CPU0
 17:          0   CPM PIC          Level        error
 18:          0   MPC8XX SIU       Level        tbint
 19:        308   CPM PIC          Level        cpm_uart
 21:          4   CPM PIC          Level        mpc8xxx_spi
 22:          0   MPC8XX SIU       Edge         ads7846
 23:      20043   MPC8XX SIU       Level        fs_enet-mac
 24:          0   MPC8XX SIU       Level        m8xx-pcmcia
 25:          9   MPC8XX SIU       Level        pata_pcmcia
 26:      10000   MPC8XX SIU       Level        pata_pcmcia
 27:        129   CPM PIC          Level        cpm_i2c
LOC:       6408   Local timer interrupts
SPU:          0   Spurious interrupts
CNT:          0   Performance monitoring interrupts
MCE:          0   Machine check exceptions
-bash-3.2#

No irq is used.

-bash-3.2# dmesg
[...]
Freeing unused kernel memory: 132k init
IRQ 26: spurious polling finished, reenabling IRQ
-bash-3.2#

Now it is back in irq mode:

-bash-3.2# cat /proc/uptime
419.65 370.56
-bash-3.2#

-bash-3.2# mount -t vfat /dev/sdb1 /home/hs/mnt
-bash-3.2# cat /proc/interrupts
           CPU0
 17:          0   CPM PIC          Level        error
 18:          0   MPC8XX SIU       Level        tbint
 19:        956   CPM PIC          Level        cpm_uart
 21:          4   CPM PIC          Level        mpc8xxx_spi
 22:          0   MPC8XX SIU       Edge         ads7846
 23:      20414   MPC8XX SIU       Level        fs_enet-mac
 24:          0   MPC8XX SIU       Level        m8xx-pcmcia
 25:          9   MPC8XX SIU       Level        pata_pcmcia
 26:      10033   MPC8XX SIU       Level        pata_pcmcia
 27:        129   CPM PIC          Level        cpm_i2c
LOC:      10880   Local timer interrupts
SPU:          0   Spurious interrupts
CNT:          0   Performance monitoring interrupts
MCE:          0   Machine check exceptions
-bash-3.2#

Now it uses the irq ...

bye,
Heiko
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