• Tejun Heo's avatar
    ahci: update PCS programming · 49f29090
    Tejun Heo authored
    
    
    For intel ones, ahci unconditionally OR'd 0xf to PCS.  This isn't
    correct for the following cases.
    
    * ich6/7m's which only implement P0 and P2 (0xf works fine tho)
    
    * ich8/9's which have six ports and needs 0x3f to enable all ports
    
    This patch updates PCS programming such that...
    
    * port_map determined by ahci_save_initial_config() is OR'd instead of 0xf
    
    * PCS is updated only if necessary (there are turned off enable bits)
    
    port_map is determined from PORTS_IMPL PCI register which is
    implemented as write or write-once register.  If the register isn't
    programmed, ahci automatically generates it from number of ports,
    which is good enough for PCS programming.  ICH6/7M are probably the
    only ones where non-contiguous enable bits are necessary && PORTS_IMPL
    isn't programmed properly but they're proven to work reliably with 0xf
    anyway.
    Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
    Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
    49f29090
ahci.c 62 KB