Convert sata_sil24 to new EH.
* When port is frozen, IRQ for the port is masked.
* sil24_softreset() doesn't need to mangle with IRQ mask anymore.
libata ensures that the port is frozen during reset.
* Only turn on interrupts which are handled by interrupt handler and
EH. As we don't handle SDB notify yet, turn it off. DEV_XCHG and
UNK_FIS are handled by EH and thus turned on.
* sil24_softreset() usually fails to recover the port after DEV_XCHG.
ATA_PORT_HARDRESET is used as recovery action for DEV_XCHG.
* sil24 may be invoked without any active command. e.g. DEV_XCHG irq
occuring while no qc in progress still triggers EH and will reset
the port and revalidate attached device.
Signed-off-by: Tejun Heo <htejun@gmail.com>
88ce7550c3