I have MPC880 based board with 24C02 I2C serial EEPROM
and I try to run Linux 2.6 on this board.
Originally I had problem:
<3>request_irq() returned -22 for CPM vector 32.
I traced the problem to the following line,
shown below as commented out (by me)
in cpm_iic_init() (drivers/i2c/algos/i2c-algo-8xx.c)
/* (*cpm_adap->setisr)(CPM_IRQ_OFFSET + CPMVEC_I2C, cpm_iic_interrupt,
cpm_int_name[CPMVEC_I2C], (void *)i2c); */
^ ^
| |
16 16
It makes the first argument to be 32 (16 + 16) and that was originally
causing error.
This error gets generated actually in request_irq() in kernel/irq/manage.c.
Specifically (I tracked it down with debug print there ) it comes from
if (irq >= NR_IRQS)
return -EINVAL;
Note that NR_IRQS is set to 32 and irq was also 32 as described above
(before my "fix" - see below) .
I have made the "fix" (it's just a kludge, I am not sure where the correct
fix should be
and what is the actual origin of this problem):
(*cpm_adap->setisr)(CPM_IRQ_OFFSET + CPMVEC_I2C - CPM_IRQ_OFFSET,
cpm_iic_interrupt, cpm_int_name[CPMVEC_I2C], (void *)i2c);
^^^^^^^^^^^^^^^
I am leaving above line "as is" just for demonstrational purpose: to show
that in the first argument the
CPM_IRQ_OFFSET is originally added and I am subtracting it back.
This gives:
cpm_iic_init[134] Install ISR for IRQ 16 CPM_IRQ_OFFSET 16
rpx_install_isr: irq: 0x10 <<<============= This is correct IRQ for I2C
on 8xx
However after this "fix" I see continuos flood of interrupts for IRQ 0x10
(dedicated to I2C on 8xx) in response to polling of 0x50 I2C address
- should be just one interrupt ...
but actually, the ISR function gets triggered in continuous non-stop flood -
I could see it with the print statement (of course I disabled this print for
the next build ...) so it chokes the processor completely.
Thanks,
Best Regards,
Alex
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
