[PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

[PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

[Mans Rullgard]

The datasheet requires that the LLP_[SD]_EN bits be cleared whenever
LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain.
Make the driver do this.

Signed-off-by: Mans Rullgard <mans@mansr.com>
---
 drivers/dma/dw/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 7067b6ddc1db..ca7cafc82f6b 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -751,6 +751,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		prev->lli.ctllo |= DWC_CTLL_INT_EN;
 
 	prev->lli.llp = 0;
+	prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 	first->txd.flags = flags;
 	first->total_len = len;
 
@@ -912,6 +913,7 @@ slave_sg_fromdev_fill_desc:
 		prev->lli.ctllo |= DWC_CTLL_INT_EN;
 
 	prev->lli.llp = 0;
+	prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 	first->total_len = total_len;
 
 	return &first->txd;
-- 
2.6.3

Re: [PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

[Andy Shevchenko]

On Mon, 2015-12-21 at 19:10 +0000, Mans Rullgard wrote:
> The datasheet requires that the LLP_[SD]_EN bits be cleared whenever
> LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain.
> Make the driver do this.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> 
> Signed-off-by: Mans Rullgard <mans@mansr.com>
> ---
>  drivers/dma/dw/core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
> index 7067b6ddc1db..ca7cafc82f6b 100644
> --- a/drivers/dma/dw/core.c
> +++ b/drivers/dma/dw/core.c
> @@ -751,6 +751,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan,
> dma_addr_t dest, dma_addr_t src,
>  		prev->lli.ctllo |= DWC_CTLL_INT_EN;
>  
>  	prev->lli.llp = 0;
> +	prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
>  	first->txd.flags = flags;
>  	first->total_len = len;
>  
> @@ -912,6 +913,7 @@ slave_sg_fromdev_fill_desc:
>  		prev->lli.ctllo |= DWC_CTLL_INT_EN;
>  
>  	prev->lli.llp = 0;
> +	prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
>  	first->total_len = total_len;
>  
>  	return &first->txd;

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

Re: [PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

[Shevchenko, Andriy]

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On Mon, 2015-12-21 at 21:34 +0200, Andy Shevchenko wrote:
> On Mon, 2015-12-21 at 19:10 +0000, Mans Rullgard wrote:
> > The datasheet requires that the LLP_[SD]_EN bits be cleared
> > whenever
> > LLP.LOC is zero, i.e. in the last descriptor of a multi-block
> > chain.
> > Make the driver do this.
> 
> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Vinod, I would like to postpone this patch for a while to make a bit
easier back porting of other dw_dmac changes wrt fix SATA on 460EX (*).

I will send it later in a bunch. Hope MÃ¥ns has no objections on this.

(*) Now I'm pretty sure that the main issues with SATA are a) wrong
master settings for transfers and LLP, and b) endiannes issue with
values in LLP. That's why I hope to have those patches coming first
with a proper Fixes: tag.

> 
> > 
> > Signed-off-by: Mans Rullgard <mans@mansr.com>
> > ---
> >  drivers/dma/dw/core.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
> > index 7067b6ddc1db..ca7cafc82f6b 100644
> > --- a/drivers/dma/dw/core.c
> > +++ b/drivers/dma/dw/core.c
> > @@ -751,6 +751,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan,
> > dma_addr_t dest, dma_addr_t src,
> >  		prev->lli.ctllo |= DWC_CTLL_INT_EN;
> >  
> >  	prev->lli.llp = 0;
> > +	prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN |
> > DWC_CTLL_LLP_S_EN);
> >  	first->txd.flags = flags;
> >  	first->total_len = len;
> >  
> > @@ -912,6 +913,7 @@ slave_sg_fromdev_fill_desc:
> >  		prev->lli.ctllo |= DWC_CTLL_INT_EN;
> >  
> >  	prev->lli.llp = 0;
> > +	prev->lli.ctllo &= ~(DWC_CTLL_LLP_D_EN |
> > DWC_CTLL_LLP_S_EN);
> >  	first->total_len = total_len;
> >  
> >  	return &first->txd;
> 

-- 
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy
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Re: [PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

[Vinod Koul]

On Tue, Dec 22, 2015 at 10:24:49PM +0530, Shevchenko, Andriy wrote:
> On Mon, 2015-12-21 at 21:34 +0200, Andy Shevchenko wrote:
> > On Mon, 2015-12-21 at 19:10 +0000, Mans Rullgard wrote:
> > > The datasheet requires that the LLP_[SD]_EN bits be cleared
> > > whenever
> > > LLP.LOC is zero, i.e. in the last descriptor of a multi-block
> > > chain.
> > > Make the driver do this.
> > 
> > Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> Vinod, I would like to postpone this patch for a while to make a bit
> easier back porting of other dw_dmac changes wrt fix SATA on 460EX (*).
> 
> I will send it later in a bunch. Hope Måns has no objections on this.

Okay by me as long as Måns is okay

-- 
~Vinod

Re: [PATCH] dmaengine: dw: clear LLP_[SD]_EN bits in last descriptor of a chain

[Viresh Kumar]

On 21-12-15, 19:10, Mans Rullgard wrote:
> The datasheet requires that the LLP_[SD]_EN bits be cleared whenever
> LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain.
> Make the driver do this.
> 
> Signed-off-by: Mans Rullgard <mans@mansr.com>
> ---
>  drivers/dma/dw/core.c | 2 ++
>  1 file changed, 2 insertions(+)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh