RE: [PATCH 4/9] dmaengine: consolidate assignment of DMA cookies
flat view
STALE5281d
REVIEWED: 6 (6M)
From: H Hartley Sweeten <hidden>
Date: 2012-03-07 00:53:27
Also in:
linux-arm-kernel
Revision v2 of 3 in this series; 2 review trailers.
Revisions (3)
- v1 [diff vs current]
- v2
- v2 current
On Tuesday, March 06, 2012 3:35 PM, Russell King wrote:
Everyone deals with assigning DMA cookies in the same way (it's part of the API so they should be), so lets consolidate the common code into a helper function to avoid this duplication. Signed-off-by: Russell King <redacted> ---
<snip>
drivers/dma/dmaengine.h | 20 ++++++++++++++++++++
<snip>
drivers/dma/ep93xx_dma.c | 9 +--------
<snip>
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diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h index 968570d..7692c86 100644 --- a/drivers/dma/dmaengine.h +++ b/drivers/dma/dmaengine.h@@ -7,4 +7,24 @@=20 #include <linux/dmaengine.h> =20 +/** + * dma_cookie_assign - assign a DMA engine cookie to the descriptor + * @tx: descriptor needing cookie + * + * Assign a unique non-zero per-channel cookie to the descriptor. + * Note: caller is expected to hold a lock to prevent concurrency. + */ +static inline dma_cookie_t dma_cookie_assign(struct dma_async_tx_descrip=
tor *tx)
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+{ + struct dma_chan *chan =3D tx->chan; + dma_cookie_t cookie; + + cookie =3D chan->cookie + 1; + if (cookie < DMA_MIN_COOKIE) + cookie =3D DMA_MIN_COOKIE; + tx->cookie =3D chan->cookie =3D cookie; + + return cookie; +} + #endif
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diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c index 3260198..e5aaae8 100644 --- a/drivers/dma/ep93xx_dma.c +++ b/drivers/dma/ep93xx_dma.c@@ -783,17 +783,10 @@ static dma_cookie_t ep93xx_dma_tx_submit(struct dma=
_async_tx_descriptor *tx)
unsigned long flags; =20 spin_lock_irqsave(&edmac->lock, flags); - - cookie =3D edmac->chan.cookie; - - if (++cookie < 0) - cookie =3D 1; + cookie =3D dma_cookie_assign(tx); =20 desc =3D container_of(tx, struct ep93xx_dma_desc, txd); =20 - edmac->chan.cookie =3D cookie; - desc->txd.cookie =3D cookie; - /* * If nothing is currently prosessed, we push this descriptor * directly to the hardware. Otherwise we put the descriptor
For ep93xx: Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>