[PATCH 1/1] dmaengine: dw: fix nollp issue

[PATCH 1/1] dmaengine: dw: fix nollp issue

[yitian]

when channel number is less than maximum number, the register
address of all channels is wrong, which causes the "nollp" flag
is set for all channels even if HW supports llp.

Signed-off-by: Yitian Bu <yitian.bu@tangramtek.com>
---
 drivers/dma/dw/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index cf1c87f..c2e9ac8 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1591,7 +1591,7 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct
dw_dma_platform_data *pdata)
 	INIT_LIST_HEAD(&dw->dma.channels);
 	for (i = 0; i < nr_channels; i++) {
 		struct dw_dma_chan	*dwc = &dw->chan[i];
-		int			r = nr_channels - i - 1;
+		int			r = DW_DMA_MAX_NR_CHANNELS - i - 1;
 
 		dwc->chan.device = &dw->dma;
 		dma_cookie_init(&dwc->chan);
-- 
1.7.12.4

[PATCH 1/1] dmaengine: dw: fix nollp issue

[Viresh Kumar]

On Sun, Sep 27, 2015 at 7:55 PM, yitian <yitian.bu@tangramtek.com> wrote:
> when channel number is less than maximum number, the register
> address of all channels is wrong, which causes the "nollp" flag
> is set for all channels even if HW supports llp.
>
> Signed-off-by: Yitian Bu <yitian.bu@tangramtek.com>
> ---
>  drivers/dma/dw/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
> index cf1c87f..c2e9ac8 100644
> --- a/drivers/dma/dw/core.c
> +++ b/drivers/dma/dw/core.c
> @@ -1591,7 +1591,7 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct
> dw_dma_platform_data *pdata)
>         INIT_LIST_HEAD(&dw->dma.channels);
>         for (i = 0; i < nr_channels; i++) {
>                 struct dw_dma_chan      *dwc = &dw->chan[i];
> -               int                     r = nr_channels - i - 1;
> +               int                     r = DW_DMA_MAX_NR_CHANNELS - i - 1;
>
>                 dwc->chan.device = &dw->dma;
>                 dma_cookie_init(&dwc->chan);

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

[PATCH 1/1] dmaengine: dw: fix nollp issue

[Andy Shevchenko]

On Mon, Sep 28, 2015 at 5:55 AM, yitian <yitian.bu@tangramtek.com> wrote:
> when channel number is less than maximum number, the register
> address of all channels is wrong, which causes the "nollp" flag
> is set for all channels even if HW supports llp.
>

Thanks for the fix, though proper one is already under review here:
http://www.spinics.net/lists/dmaengine/msg06143.html

You might break a channel prioritization.

> Signed-off-by: Yitian Bu <yitian.bu@tangramtek.com>
> ---
>  drivers/dma/dw/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
> index cf1c87f..c2e9ac8 100644
> --- a/drivers/dma/dw/core.c
> +++ b/drivers/dma/dw/core.c
> @@ -1591,7 +1591,7 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct
> dw_dma_platform_data *pdata)
>         INIT_LIST_HEAD(&dw->dma.channels);
>         for (i = 0; i < nr_channels; i++) {
>                 struct dw_dma_chan      *dwc = &dw->chan[i];
> -               int                     r = nr_channels - i - 1;
> +               int                     r = DW_DMA_MAX_NR_CHANNELS - i - 1;
>
>                 dwc->chan.device = &dw->dma;
>                 dma_cookie_init(&dwc->chan);
> --
> 1.7.12.4
>
>
>
> --
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-- 
With Best Regards,
Andy Shevchenko