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    Subject[PATCH 3.13 039/120] spidev: fix hang when transfer_one_message fails
    Date
    3.13-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Daniel Santos <daniel.santos@pobox.com>

    commit e120cc0dcf2880a4c5c0a6cb27b655600a1cfa1d upstream.

    This corrects a problem in spi_pump_messages() that leads to an spi
    message hanging forever when a call to transfer_one_message() fails.
    This failure occurs in my MCP2210 driver when the cs_change bit is set
    on the last transfer in a message, an operation which the hardware does
    not support.

    Rationale
    Since the transfer_one_message() returns an int, we must presume that it
    may fail. If transfer_one_message() should never fail, it should return
    void. Thus, calls to transfer_one_message() should properly manage a
    failure.

    Fixes: ffbbdd21329f3 (spi: create a message queueing infrastructure)
    Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
    Signed-off-by: Mark Brown <broonie@linaro.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/spi/spi.c | 4 +++-
    1 file changed, 3 insertions(+), 1 deletion(-)

    --- a/drivers/spi/spi.c
    +++ b/drivers/spi/spi.c
    @@ -735,7 +735,9 @@ static void spi_pump_messages(struct kth
    ret = master->transfer_one_message(master, master->cur_msg);
    if (ret) {
    dev_err(&master->dev,
    - "failed to transfer one message from queue\n");
    + "failed to transfer one message from queue: %d\n", ret);
    + master->cur_msg->status = ret;
    + spi_finalize_current_message(master);
    return;
    }
    }



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