> -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Dan Williams > Sent: Sunday, September 02, 2012 4:41 PM > To: Liu Qiang-B32616 > Cc: [email protected]; [email protected]; linux- > [email protected]; [email protected]; Phillips Kim-R1AAHA; > [email protected]; [email protected]; [email protected]; > [email protected]; Li Yang-R58472; Tabi Timur-B04825 > Subject: Re: [PATCH v7 6/8] fsl-dma: use spin_lock_bh to instead of > spin_lock_irqsave > > On Thu, Aug 9, 2012 at 1:23 AM, <[email protected]> wrote: > > From: Qiang Liu <[email protected]> > > > > 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. > > It seems you are coordinating fsl-dma copy and talitos xor operations. > It looks like fsl-dma will be called through > talitos_process_pending()->dma_run_dependencies(), which is > potentially called in hard irq context. > > This all comes back to the need to fix raid offload to manage the > channels explicitly rather than the current dependency chains. So you mean I must implement talitos_run_dependencies() and fsldma_run_dependencies()? Invoke async_tx->callback() respectively. How about avoiding irq context in talitos?
> > -- > Dan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
