• Tejun Heo's avatar
    libata: improve post-reset device ready test · 78ab88f0
    Tejun Heo authored
    Some controllers (jmb and inic162x) use 0x77 and 0x7f to indicate that
    the device isn't ready yet.  It looks like they use 0xff if device
    presence is detected but connection isn't established.  0x77 or 0x7f
    after connection is established and use the value from signature FIS
    after receiving it.
    
    This patch implements ata_check_ready(), which takes TF status value
    and determines whether the port is ready or not considering the above
    and other conditions, and use it in @check_ready() functions.  This is
    safe as both 0x77 and 0x7f aren't valid ready status value even though
    they have BSY bit cleared.
    
    This fixes hot plug detection failures which can be triggered with
    certain drives if they aren't already spun up when the data connector
    is hot plugged.
    
    Tested on sil, sil24, ahci (jmb/ich), piix and inic162x combined with
    eight drives from all major vendors.
    Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
    Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
    78ab88f0
libata-sff.c 70 KB