Patchwork [v1,1/5] dmaengine: dw: Fix FIFO size for Intel Merrifield

login
register
mail settings
Submitter Andy Shevchenko
Date Nov. 30, 2018, 8:36 p.m.
Message ID <20181130203646.68615-1-andriy.shevchenko@linux.intel.com>
Download mbox | patch
Permalink /patch/669521/
State New
Headers show

Comments

Andy Shevchenko - Nov. 30, 2018, 8:36 p.m.
Intel Merrifield has a reduced size of FIFO used in iDMA 32-bit controller,
i.e. 512 bytes instead of 1024.

Fix this by partitioning it as 64 bytes per channel.

Note, in the future we might switch to 'fifo-size' property instead of
hard coded value.

Fixes: 199244d69458 ("dmaengine: dw: add support of iDMA 32-bit hardware")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable@vger.kernel.org
---
 drivers/dma/dw/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
Andy Shevchenko - Dec. 4, 2018, 5:03 p.m.
On Fri, Nov 30, 2018 at 10:36:42PM +0200, Andy Shevchenko wrote:
> Intel Merrifield has a reduced size of FIFO used in iDMA 32-bit controller,
> i.e. 512 bytes instead of 1024.
> 
> Fix this by partitioning it as 64 bytes per channel.
> 
> Note, in the future we might switch to 'fifo-size' property instead of
> hard coded value.

v2 of the series is coming soon this week, so, don't consider this one.

> 
> Fixes: 199244d69458 ("dmaengine: dw: add support of iDMA 32-bit hardware")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/dma/dw/core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
> index d0c3e50b39fb..e85b078fc207 100644
> --- a/drivers/dma/dw/core.c
> +++ b/drivers/dma/dw/core.c
> @@ -1059,12 +1059,12 @@ static void dwc_issue_pending(struct dma_chan *chan)
>  /*
>   * Program FIFO size of channels.
>   *
> - * By default full FIFO (1024 bytes) is assigned to channel 0. Here we
> + * By default full FIFO (512 bytes) is assigned to channel 0. Here we
>   * slice FIFO on equal parts between channels.
>   */
>  static void idma32_fifo_partition(struct dw_dma *dw)
>  {
> -	u64 value = IDMA32C_FP_PSIZE_CH0(128) | IDMA32C_FP_PSIZE_CH1(128) |
> +	u64 value = IDMA32C_FP_PSIZE_CH0(64) | IDMA32C_FP_PSIZE_CH1(64) |
>  		    IDMA32C_FP_UPDATE;
>  	u64 fifo_partition = 0;
>  
> -- 
> 2.19.2
>

Patch

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index d0c3e50b39fb..e85b078fc207 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1059,12 +1059,12 @@  static void dwc_issue_pending(struct dma_chan *chan)
 /*
  * Program FIFO size of channels.
  *
- * By default full FIFO (1024 bytes) is assigned to channel 0. Here we
+ * By default full FIFO (512 bytes) is assigned to channel 0. Here we
  * slice FIFO on equal parts between channels.
  */
 static void idma32_fifo_partition(struct dw_dma *dw)
 {
-	u64 value = IDMA32C_FP_PSIZE_CH0(128) | IDMA32C_FP_PSIZE_CH1(128) |
+	u64 value = IDMA32C_FP_PSIZE_CH0(64) | IDMA32C_FP_PSIZE_CH1(64) |
 		    IDMA32C_FP_UPDATE;
 	u64 fifo_partition = 0;