[PATCH v6 6/8] fsl-dma: use spin_lock_bh to instead of spin_lock_irqsave

Arnd Bergmann arnd at arndb.de
Mon Aug 6 21:57:17 EST 2012

On Monday 06 August 2012, qiang.liu at freescale.com wrote:
> From: Qiang Liu <qiang.liu at freescale.com>
> The use of spin_lock_irqsave() is a stronger locking mechanism than is
> required throughout the driver. The minimum locking required should be
> used instead. Interrupts will be turned off and context will be saved,
> there is needless to use irqsave.
> Change all instances of spin_lock_irqsave() to spin_lock_bh().
> All manipulation of protected fields is done using tasklet context or
> weaker, which makes spin_lock_bh() the correct choice.
> Cc: Dan Williams <dan.j.williams at intel.com>
> Cc: Dan Williams <dan.j.williams at gmail.com>
> Cc: Vinod Koul <vinod.koul at intel.com>
> Cc: Li Yang <leoli at freescale.com>
> Cc: Timur Tabi <timur at freescale.com>
> Signed-off-by: Qiang Liu <qiang.liu at freescale.com>
> Acked-by: Ira W. Snyder <iws at ovro.caltech.edu>

Acked-by: Arnd Bergmann <arnd at arndb.de>

You could actually change the use of spin_lock_bh inside of the tasklet
function (dma_do_tasklet) do just spin_lock(), because softirqs are
already disabled there, but your version is also ok.

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