• David Fries's avatar
    W1: ds2490.c simplify and fix ds_touch_bit · 6e10f654
    David Fries authored
    Simplify and fix ds_touch_bit.  If a device is attached in the middle of a
    bus search the status register will return more than the default 16 bytes.
     The additional bytes indicate that it has detected a new device.  The way
    ds_wait_status is coded, if it doesn't read 16 status bytes it returns an
    error value.  ds_touch_bit then will detect that error and return an
    error.  In that case it doesn't read the input buffer and returns
    uninitialized data.  It doesn't stop there.  The next transaction will not
    expect the extra byte in the input buffer and the short read will cause an
    error and clear out both the old byte and new data in the input buffer.
    Just ignore the value of ds_wait_status.  It is still required to wait
    until ds2490 is again idle and there is data to read when ds_recv_data is
    called.  This also removes the while loop.  None of the other commands
    wait and verify that the issued command is in the status register.
    Signed-off-by: default avatarDavid Fries <david@fries.net>
    Signed-off-by: default avatarEvgeniy Polyakov <johnpol@2ka.mipt.ru>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
ds2490.c 20.3 KB