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    Subject[patch 083/164] ARM: 6146/1: sa1111: Prevent deadlock in resume path
    2.6.33-stable review patch.  If anyone has any objections, please let me know.

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

    From: =?UTF-8?q?Marek=20Va=C5=A1ut?= <marek.vasut@gmail.com>

    commit 3defb2476166445982a90c12d33f8947e75476c4 upstream.

    This patch reorganises the sa1111_resume() function in a manner the spinlock
    happens after calling the sa1111_wake(). This fixes two bugs:

    1) This function called sa1111_wake() which tried to claim the same spinlock
    the sa1111_resume() already claimed. This would result in certain deadlock.

    Original idea for this part: Russell King <rmk+kernel@arm.linux.org.uk>

    2) The function didn't unlock the spinlock in case the chip didn't report
    correct ID.

    Original idea for this part: Julia Lawall <julia@diku.dk>

    Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
    Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    arch/arm/common/sa1111.c | 9 +++++++--
    1 file changed, 7 insertions(+), 2 deletions(-)

    --- a/arch/arm/common/sa1111.c
    +++ b/arch/arm/common/sa1111.c
    @@ -887,8 +887,6 @@ static int sa1111_resume(struct platform
    if (!save)
    return 0;

    - spin_lock_irqsave(&sachip->lock, flags);
    -
    /*
    * Ensure that the SA1111 is still here.
    * FIXME: shouldn't do this here.
    @@ -905,6 +903,13 @@ static int sa1111_resume(struct platform
    * First of all, wake up the chip.
    */
    sa1111_wake(sachip);
    +
    + /*
    + * Only lock for write ops. Also, sa1111_wake must be called with
    + * released spinlock!
    + */
    + spin_lock_irqsave(&sachip->lock, flags);
    +
    sa1111_writel(0, sachip->base + SA1111_INTC + SA1111_INTEN0);
    sa1111_writel(0, sachip->base + SA1111_INTC + SA1111_INTEN1);




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