Re: [PATCH] dmaengine: imx-sdma: Add device to device support

[Shengjiu Wang <shengjiu.wang@freescale.com>]

On Fri, Jul 10, 2015 at 11:52:05AM +0530, Vinod Koul wrote:
> On Tue, Jul 07, 2015 at 01:24:22PM +0800, Shengjiu Wang wrote:
> > > why not use set_bit(), you are modifying driver memory
> > Original driver all use the __set_bit. do you think we need to change
> > all the __set_bit to set_bit? And from the header file "arch/arm/include/asm
> > /bitops.h", the set_bit is same as __set_bit.
> New changes should be rightly done. __xxx denotes typically internal API to
> a subsystem, so if they are same I would suggest to use set_bit()
Ok, I agree with you.
> 
> > > > +	/*
> > > > +	 * If LWML(src_maxburst) > HWML(dst_maxburst), we need
> > > > +	 * swap LWML and HWML of INFO(A.3.2.5.1), also need swap
> > > > +	 * r0(event_mask[1]) and r1(event_mask[0]).
> > > > +	 */
> > > > +	if (lwml > hwml) {
> > > > +		sdmac->watermark_level &= ~0xff00ff;
> > > Magic number?
> ??
I have add a description on V2 patch for the watermark_level definition.
> 
> > > Okay the direction is depreciated, so can you store both source and
> > > destination and use them based on direction in prepare()
> > > 
> > > Also I see driver is not doing this, so while at it, can you fix this is
> > > current code as well
> > > 
> > which prepare() do you mean? sdma_prep_dma_cyclic, sdma_prep_slave_sg?
> both have direction as an argument. So you need to use that
I have removed the direction checking. So I think don't need to change the
sdma_prep_dma_cyclic, sdma_prep_slave_sg.

Anyway please review the V2 patch for this, I have sent it out. In V2, I still
use the __set_bit. After you review the V2 patch, I will change them together.

Thanks.
wang shengjiu
> 
> -- 
> ~Vinod
>