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[1/3] dmaengine: at_xdmac: align descriptors on 64 bits

Message ID 1463064854-6719-1-git-send-email-ludovic.desroches@atmel.com (mailing list archive)
State Accepted
Headers show

Commit Message

Ludovic Desroches May 12, 2016, 2:54 p.m. UTC
Having descriptors aligned on 64 bits allows update CNDA and CUBC in an
atomic way.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel
eXtended DMA Controller driver")
Cc: stable@vger.kernel.org #v4.1 and later
---
 drivers/dma/at_xdmac.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Nicolas Ferre May 13, 2016, 12:27 p.m. UTC | #1
Le 12/05/2016 16:54, Ludovic Desroches a écrit :
> Having descriptors aligned on 64 bits allows update CNDA and CUBC in an
> atomic way.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel
> eXtended DMA Controller driver")
> Cc: stable@vger.kernel.org #v4.1 and later

Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>

> ---
>  drivers/dma/at_xdmac.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index 8e304b1..ba9b0b7 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -242,7 +242,7 @@ struct at_xdmac_lld {
>  	u32		mbr_dus;	/* Destination Microblock Stride Register */
>  };
>  
> -
> +/* 64-bit alignment needed to update CNDA and CUBC registers in an atomic way. */
>  struct at_xdmac_desc {
>  	struct at_xdmac_lld		lld;
>  	enum dma_transfer_direction	direction;
> @@ -253,7 +253,7 @@ struct at_xdmac_desc {
>  	unsigned int			xfer_size;
>  	struct list_head		descs_list;
>  	struct list_head		xfer_node;
> -};
> +} __aligned(sizeof(u64));
>  
>  static inline void __iomem *at_xdmac_chan_reg_base(struct at_xdmac *atxdmac, unsigned int chan_nb)
>  {
>
Vinod Koul May 30, 2016, 5:18 a.m. UTC | #2
On Thu, May 12, 2016 at 04:54:08PM +0200, Ludovic Desroches wrote:
> Having descriptors aligned on 64 bits allows update CNDA and CUBC in an
> atomic way.

Applied all, thanks
diff mbox

Patch

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 8e304b1..ba9b0b7 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -242,7 +242,7 @@  struct at_xdmac_lld {
 	u32		mbr_dus;	/* Destination Microblock Stride Register */
 };
 
-
+/* 64-bit alignment needed to update CNDA and CUBC registers in an atomic way. */
 struct at_xdmac_desc {
 	struct at_xdmac_lld		lld;
 	enum dma_transfer_direction	direction;
@@ -253,7 +253,7 @@  struct at_xdmac_desc {
 	unsigned int			xfer_size;
 	struct list_head		descs_list;
 	struct list_head		xfer_node;
-};
+} __aligned(sizeof(u64));
 
 static inline void __iomem *at_xdmac_chan_reg_base(struct at_xdmac *atxdmac, unsigned int chan_nb)
 {