Dear all
This days I came to a problem like this:
Environment:linux kernel 2.6.20, PPC 405EP bubinga demo board.
We have tested two PCI2IDE cards in this board,A)silicon Image's
(cpu:cmd649);B)IT8212F's.The A card with a harddisk,which is well recognised by
the demo board;but the same harddisk in B card, can't be recognised by the
board,only recognised the PCI card.We trace the kernel,found something
different in this funtion in the file linux-2.6.20/drivers/ide/ide-iops.c:
++++++++++++++++++++++++++++++++++++++++++
int ide_wait_not_busy(ide_hwif_t *hwif, unsigned long timeout)
{
u8 stat = 0;
u8 i = 0;
while(timeout--) {
/*
* Turn this into a schedule() sleep once I'm sure
* about locking issues (2.5 work ?).
* hwif->io_ports[IDE_STATUS_OFFSET] = 0xFFEF
*/
mdelay(1);
stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
printk(KERN_INFO "hwif->io_ports[IDE_STATUS_OFFSET] ==> %4x, 222222STAT ==>
%4x\n",hwif->io_ports[IDE_STATUS_OFFSET],stat);
if ((stat & BUSY_STAT) == 0){
printk(KERN_INFO "BUSYING................\n");
return 0;
}
/*
* Assume a value of 0xff means nothing is connected to
* the interface and it doesn't implement the pull-down
* resistor on D7.n isa_io_base = e7fee000
*/
if (stat == 0xff){
printk(KERN_INFO "NODEV................ \n");
return -ENODEV;
}
touch_softlockup_watchdog();
touch_nmi_watchdog();
}
return -EBUSY;
}
+++++++++++++++++++++++++++++++++++++++++++++++++++
stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
printk(KERN_INFO "hwif->io_ports[IDE_STATUS_OFFSET] ==> %4x, 222222STAT ==>
%4x\n",hwif->io_ports[IDE_STATUS_OFFSET],stat);
By printing this two parameters, we found that the former parameter is the same
in two cards,but the value of "stat" varies between the two
cards.A card,stat equals to 0x50;B card,stat equals to 0xFF,and it keeps the
same,won't change.
I'm puzzled about this.Is it about the driver of IT821x.c in the
kernel?or something else?
Any advise is welcomed.Thank you.
Sincerely
Tony
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