dmaengine: ensure all DMA engine drivers initialize their cookies

Ensure all DMA engine drivers initialize their cookies in the same way,
so that they all behave in a similar fashion.  This means their first
issued cookie will be 2 rather than 1, and will increment to INT_MAX
before returning 1 and starting over.

In connection with this, Dan Williams said:
> Russell King wrote:
> > Secondly, some DMA engine drivers initialize the dma_chan cookie to 0,
> > others to 1.  Is there a reason for this, or are these all buggy?
>
> I know that ioat and iop-adma expect 0 to mean "I have cleaned up this
> descriptor and it is idle", and would break if zero was an in-flight
> cookie value.  The reserved usage of zero is an driver internal
> concern, but I have no problem formalizing it as a reserved value.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
This commit is contained in:
Russell King - ARM Linux 2012-03-06 22:36:27 +00:00 committed by Vinod Koul
parent 2a926e4602
commit 8ac695463f
9 changed files with 9 additions and 0 deletions

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@ -1292,6 +1292,7 @@ static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
chan->idle = true;
chan->common.device = &fdev->common;
dma_cookie_init(&chan->common);
/* find the IRQ line, if it exists in the device tree */
chan->irq = irq_of_parse_and_map(node, 0);

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@ -347,6 +347,7 @@ static int __init imxdma_probe(struct platform_device *pdev)
spin_lock_init(&imxdmac->lock);
imxdmac->chan.device = &imxdma->dma_device;
dma_cookie_init(&imxdmac->chan);
imxdmac->channel = i;
/* Add the channel to the DMAC list */

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@ -1355,6 +1355,7 @@ static int __init sdma_probe(struct platform_device *pdev)
spin_lock_init(&sdmac->lock);
sdmac->chan.device = &sdma->dma_device;
dma_cookie_init(&sdmac->chan);
sdmac->channel = i;
/*

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@ -109,6 +109,7 @@ void ioat_init_channel(struct ioatdma_device *device, struct ioat_chan_common *c
chan->reg_base = device->reg_base + (0x80 * (idx + 1));
spin_lock_init(&chan->cleanup_lock);
chan->common.device = dma;
dma_cookie_init(&chan->common);
list_add_tail(&chan->common.device_node, &dma->channels);
device->idx[idx] = chan;
init_timer(&chan->timer);

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@ -1545,6 +1545,7 @@ static int __devinit iop_adma_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&iop_chan->chain);
INIT_LIST_HEAD(&iop_chan->all_slots);
iop_chan->common.device = dma_dev;
dma_cookie_init(&iop_chan->common);
list_add_tail(&iop_chan->common.device_node, &dma_dev->channels);
if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {

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@ -1193,6 +1193,7 @@ static int __devinit mv_xor_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&mv_chan->completed_slots);
INIT_LIST_HEAD(&mv_chan->all_slots);
mv_chan->common.device = dma_dev;
dma_cookie_init(&mv_chan->common);
list_add_tail(&mv_chan->common.device_node, &dma_dev->channels);

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@ -618,6 +618,7 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
mxs_chan->mxs_dma = mxs_dma;
mxs_chan->chan.device = &mxs_dma->dma_device;
dma_cookie_init(&mxs_chan->chan);
tasklet_init(&mxs_chan->tasklet, mxs_dma_tasklet,
(unsigned long) mxs_chan);

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@ -4497,6 +4497,7 @@ static int __devinit ppc440spe_adma_probe(struct platform_device *ofdev)
INIT_LIST_HEAD(&chan->all_slots);
chan->device = adev;
chan->common.device = &adev->common;
dma_cookie_init(&chan->common);
list_add_tail(&chan->common.device_node, &adev->common.channels);
tasklet_init(&chan->irq_tasklet, ppc440spe_adma_tasklet,
(unsigned long)chan);

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@ -1089,6 +1089,7 @@ static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
/* reference struct dma_device */
new_sh_chan->common.device = &shdev->common;
dma_cookie_init(&new_sh_chan->common);
new_sh_chan->dev = shdev->common.dev;
new_sh_chan->id = id;