Thursday, August 20, 2009, 5:55:47 PM, Jeff Garzik wrote:
> Have you verified this is needed, under libata? We already have several
> waits...
Unfortunately it is needed. It is embedded system, where bootloader
always tries to boot from the first device (dvd-rom). Second device
(hard disk) is not yet ready when kernel is loaded from flash and does
probe.
I placed the code into dev_select callback
void jasper_dev_select(struct ata_port *ap, unsigned int device)
{
u8 tmp;
if (device == 0)
tmp = ATA_DEVICE_OBS;
else
tmp = ATA_DEVICE_OBS | ATA_DEV1;
iowrite8(tmp, ap->ioaddr.device_addr);
ata_pause(ap); /* needed; also flushes, for mmio */
if (device && firstSlaveAccess) {
firstSlaveAccess = 0;
printk("waiting for drive to settle...\n");
if (ioread8(ap->ioaddr.device_addr) != tmp) {
int rc;
for (rc = 0; rc < 150; rc++) {
iowrite8(tmp, ap->ioaddr.device_addr);
mdelay(50); //ata_pause(ap);
if (ioread8(ap->ioaddr.device_addr) == tmp)
break;
}
}
}
}
It takes about 30 cycles (1.5s) to select slave for the first time.
--
Best regards,
Andrei mailto:andrei.martynov@xxxxxx
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