• Mariusz Bialonczyk's avatar
    w1: fix the resume command API · 62909da8
    Mariusz Bialonczyk authored
    >From the DS2408 datasheet [1]:
    "Resume Command function checks the status of the RC flag and, if it is set,
     directly transfers control to the control functions, similar to a Skip ROM
     command. The only way to set the RC flag is through successfully executing
     the Match ROM, Search ROM, Conditional Search ROM, or Overdrive-Match ROM
     command"
    
    The function currently works perfectly fine in a multidrop bus, but when we
    have only a single slave connected, then only a Skip ROM is used and Match
    ROM is not called at all. This is leading to problems e.g. with single one
    DS2408 connected, as the Resume Command is not working properly and the
    device is responding with failing results after the Resume Command.
    
    This commit is fixing this by using a Skip ROM instead in those cases.
    The bandwidth / performance advantage is exactly the same.
    
    Refs:
    [1] https://datasheets.maximintegrated.com/en/ds/DS2408.pdfSigned-off-by: default avatarMariusz Bialonczyk <manio@skyboo.net>
    Reviewed-by: default avatarJean-Francois Dagenais <jeff.dagenais@gmail.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    62909da8
w1_io.c 12 KB