Messages in this thread | | | From | Liu Qiang-B32616 <> | Subject | RE: [PATCH v6 6/8] fsl-dma: use spin_lock_bh to instead of spin_lock_irqsave | Date | Tue, 7 Aug 2012 02:45:45 +0000 |
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> -----Original Message----- > From: Arnd Bergmann [mailto:arnd@arndb.de] > Sent: Monday, August 06, 2012 7:57 PM > To: Liu Qiang-B32616 > Cc: linux-crypto@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; > dan.j.williams@intel.com; linux-kernel@vger.kernel.org; > dan.j.williams@gmail.com; vinod.koul@intel.com; Phillips Kim-R1AAHA; > herbert@gondor.hengli.com.au; davem@davemloft.net; > gregkh@linuxfoundation.org; Li Yang-R58472; Tabi Timur-B04825 > Subject: Re: [PATCH v6 6/8] fsl-dma: use spin_lock_bh to instead of > spin_lock_irqsave > > On Monday 06 August 2012, qiang.liu@freescale.com wrote: > > > > From: Qiang Liu <qiang.liu@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@intel.com> > > Cc: Dan Williams <dan.j.williams@gmail.com> > > Cc: Vinod Koul <vinod.koul@intel.com> > > Cc: Li Yang <leoli@freescale.com> > > Cc: Timur Tabi <timur@freescale.com> > > Signed-off-by: Qiang Liu <qiang.liu@freescale.com> > > Acked-by: Ira W. Snyder <iws@ovro.caltech.edu> > > Acked-by: Arnd Bergmann <arnd@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. Yes, you are right, it will disable softirq. Thank you very much.
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