ata_bus_reset9
Reset host port and associated ata channel
Usage
void ata_bus_reset(struct ata_port * ap);
Arguments
ap
port to reset
Overview
This is typically the first time we actually start issuing commands to the ATA channel. We wait for BSY to clear, then issue EXECUTE DEVICE DIAGNOSTIC command, polling for its result. Determine what devices, if any, are on the channel by looking at the device 0/1 error register. Look at the signature stored in each device's taskfile registers, to determine if the device is ATA or ATAPI.
Locking
PCI/etc. bus probe sem. Obtains host_set lock.
Side effects
Sets ATA_FLAG_DISABLED if bus reset fails.