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    Subject[PATCH 4.19 093/243] dmaengine: coh901318: Fix a double-lock bug
    Date
    From: Jia-Ju Bai <baijiaju1990@gmail.com>

    [ Upstream commit 627469e4445b9b12e0229b3bdf8564d5ce384dd7 ]

    The function coh901318_alloc_chan_resources() calls spin_lock_irqsave()
    before calling coh901318_config().
    But coh901318_config() calls spin_lock_irqsave() again in its
    definition, which may cause a double-lock bug.

    Because coh901318_config() is only called by
    coh901318_alloc_chan_resources(), the bug fix is to remove the
    calls to spin-lock and -unlock functions in coh901318_config().

    Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
    Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
    Signed-off-by: Vinod Koul <vkoul@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/dma/coh901318.c | 4 ----
    1 file changed, 4 deletions(-)

    --- a/drivers/dma/coh901318.c
    +++ b/drivers/dma/coh901318.c
    @@ -1802,8 +1802,6 @@ static int coh901318_config(struct coh90
    int channel = cohc->id;
    void __iomem *virtbase = cohc->base->virtbase;

    - spin_lock_irqsave(&cohc->lock, flags);
    -
    if (param)
    p = param;
    else
    @@ -1823,8 +1821,6 @@ static int coh901318_config(struct coh90
    coh901318_set_conf(cohc, p->config);
    coh901318_set_ctrl(cohc, p->ctrl_lli_last);

    - spin_unlock_irqrestore(&cohc->lock, flags);
    -
    return 0;
    }


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