<[email protected]> writes:

> This is a note to let you know that I've just added the patch titled
>
>     dma: pl330: Fix cyclic transfers
>
> to the 3.4-stable tree which can be found at:
>     
> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>
> The filename of the patch is:
>      dma-pl330-fix-cyclic-transfers.patch
> and it can be found in the queue-3.4 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <[email protected]> know about it.
>

While working on this patch for the 3.5 kernel I found it breaks the
kernel build for 2 reasons:

 * is_slave_direction() is not defined (although you could cherry-pick
   61cc13a51bcff737ce02d2047834171c0365b00d commit)

 * function pl330_prep_dma_cyclic() signature doesn't contain the
   'flags' parameter introduced by commit
   ec8b5e48c03790a68cb875fe5064007a9cbdfdd0

I checked 3.4 kernel and looks like you'll have the same issues.

Cheers,
-- 
Luis


>
> From fc51446021f42aca8906e701fc2292965aafcb15 Mon Sep 17 00:00:00
>2001
> From: Lars-Peter Clausen <[email protected]>
> Date: Tue, 23 Jul 2013 10:24:50 +0200
> Subject: dma: pl330: Fix cyclic transfers
>
> From: Lars-Peter Clausen <[email protected]>
>
> commit fc51446021f42aca8906e701fc2292965aafcb15 upstream.
>
> Allocate a descriptor for each period of a cyclic transfer, not just the 
> first.
> Also since the callback needs to be called for each finished period make sure 
> to
> initialize the callback and callback_param fields of each descriptor in a 
> cyclic
> transfer.
>
> Signed-off-by: Lars-Peter Clausen <[email protected]>
> Signed-off-by: Vinod Koul <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
>
> ---
>  drivers/dma/pl330.c |   93 
> +++++++++++++++++++++++++++++++++++++---------------
>  1 file changed, 67 insertions(+), 26 deletions(-)
>
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -2511,6 +2511,10 @@ static dma_cookie_t pl330_tx_submit(stru
>       /* Assign cookies to all nodes */
>       while (!list_empty(&last->node)) {
>               desc = list_entry(last->node.next, struct dma_pl330_desc, node);
> +             if (pch->cyclic) {
> +                     desc->txd.callback = last->txd.callback;
> +                     desc->txd.callback_param = last->txd.callback_param;
> +             }
>  
>               dma_cookie_assign(&desc->txd);
>  
> @@ -2694,45 +2698,82 @@ static struct dma_async_tx_descriptor *p
>               size_t period_len, enum dma_transfer_direction direction,
>               void *context)
>  {
> -     struct dma_pl330_desc *desc;
> +     struct dma_pl330_desc *desc = NULL, *first = NULL;
>       struct dma_pl330_chan *pch = to_pchan(chan);
> +     struct dma_pl330_dmac *pdmac = pch->dmac;
> +     unsigned int i;
>       dma_addr_t dst;
>       dma_addr_t src;
>  
> -     desc = pl330_get_desc(pch);
> -     if (!desc) {
> -             dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
> -                     __func__, __LINE__);
> +     if (len % period_len != 0)
>               return NULL;
> -     }
>  
> -     switch (direction) {
> -     case DMA_MEM_TO_DEV:
> -             desc->rqcfg.src_inc = 1;
> -             desc->rqcfg.dst_inc = 0;
> -             desc->req.rqtype = MEMTODEV;
> -             src = dma_addr;
> -             dst = pch->fifo_addr;
> -             break;
> -     case DMA_DEV_TO_MEM:
> -             desc->rqcfg.src_inc = 0;
> -             desc->rqcfg.dst_inc = 1;
> -             desc->req.rqtype = DEVTOMEM;
> -             src = pch->fifo_addr;
> -             dst = dma_addr;
> -             break;
> -     default:
> +     if (!is_slave_direction(direction)) {
>               dev_err(pch->dmac->pif.dev, "%s:%d Invalid dma direction\n",
>               __func__, __LINE__);
>               return NULL;
>       }
>  
> -     desc->rqcfg.brst_size = pch->burst_sz;
> -     desc->rqcfg.brst_len = 1;
> +     for (i = 0; i < len / period_len; i++) {
> +             desc = pl330_get_desc(pch);
> +             if (!desc) {
> +                     dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch 
> desc\n",
> +                             __func__, __LINE__);
>  
> -     pch->cyclic = true;
> +                     if (!first)
> +                             return NULL;
> +
> +                     spin_lock_irqsave(&pdmac->pool_lock, flags);
> +
> +                     while (!list_empty(&first->node)) {
> +                             desc = list_entry(first->node.next,
> +                                             struct dma_pl330_desc, node);
> +                             list_move_tail(&desc->node, &pdmac->desc_pool);
> +                     }
> +
> +                     list_move_tail(&first->node, &pdmac->desc_pool);
> +
> +                     spin_unlock_irqrestore(&pdmac->pool_lock, flags);
> +
> +                     return NULL;
> +             }
> +
> +             switch (direction) {
> +             case DMA_MEM_TO_DEV:
> +                     desc->rqcfg.src_inc = 1;
> +                     desc->rqcfg.dst_inc = 0;
> +                     desc->req.rqtype = MEMTODEV;
> +                     src = dma_addr;
> +                     dst = pch->fifo_addr;
> +                     break;
> +             case DMA_DEV_TO_MEM:
> +                     desc->rqcfg.src_inc = 0;
> +                     desc->rqcfg.dst_inc = 1;
> +                     desc->req.rqtype = DEVTOMEM;
> +                     src = pch->fifo_addr;
> +                     dst = dma_addr;
> +                     break;
> +             default:
> +                     break;
> +             }
>  
> -     fill_px(&desc->px, dst, src, period_len);
> +             desc->rqcfg.brst_size = pch->burst_sz;
> +             desc->rqcfg.brst_len = 1;
> +             fill_px(&desc->px, dst, src, period_len);
> +
> +             if (!first)
> +                     first = desc;
> +             else
> +                     list_add_tail(&desc->node, &first->node);
> +
> +             dma_addr += period_len;
> +     }
> +
> +     if (!desc)
> +             return NULL;
> +
> +     pch->cyclic = true;
> +     desc->txd.flags = flags;
>  
>       return &desc->txd;
>  }
>
>
> Patches currently in stable-queue which might be from [email protected] are
>
> queue-3.4/dma-pl330-fix-cyclic-transfers.patch
> --
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