Re: [PATCH 2/2] OMAP: DMA: clear interrupt status correctly

[Kevin Hilman <khilman@ti.com>]

Adrian Hunter <adrian.hunter@nokia.com> writes:

> From fffa19df17d73c1ed2e8c65c0b6604ee1dddff84 Mon Sep 17 00:00:00 2001
> From: Adrian Hunter <adrian.hunter@nokia.com>
> Date: Wed, 24 Nov 2010 13:23:21 +0200
> Subject: [PATCH] OMAP: DMA: clear interrupt status correctly
>
> When clearing the DMA channel, clear all status bits.
>
> When handling a DMA interrupt, clear only the interrupt
> status bits that have been read and are passed to the
> channel's interrupt handler, not every status bit.
>
> Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

Looks like a fix that should go into 2.6.38-rc2.  Can you repost and Cc
linux-arm-kernel as well?

Thanks,

Kevin

> ---
>  arch/arm/plat-omap/dma.c |    7 +++----
>  1 files changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
> index c4b2b47..8536308 100644
> --- a/arch/arm/plat-omap/dma.c
> +++ b/arch/arm/plat-omap/dma.c
> @@ -53,7 +53,7 @@ enum { DMA_CHAIN_STARTED, DMA_CHAIN_NOTSTARTED };
>  #endif
>  #define OMAP_DMA_ACTIVE			0x01
> -#define OMAP2_DMA_CSR_CLEAR_MASK	0xffe
> +#define OMAP2_DMA_CSR_CLEAR_MASK	0xffffffff
>  #define OMAP_FUNC_MUX_ARM_BASE		(0xfffe1000 + 0xec)
>  @@ -1873,7 +1873,7 @@ static int omap2_dma_handle_ch(int ch)
>  		printk(KERN_INFO "DMA misaligned error with device %d\n",
>  		       dma_chan[ch].dev_id);
>  -	p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, ch);
> +	p->dma_write(status, CSR, ch);
>  	p->dma_write(1 << ch, IRQSTATUS_L0, ch);
>  	/* read back the register to flush the write */
>  	p->dma_read(IRQSTATUS_L0, ch);
> @@ -1893,10 +1893,9 @@ static int omap2_dma_handle_ch(int ch)
>  			OMAP_DMA_CHAIN_INCQHEAD(chain_id);
>  		status = p->dma_read(CSR, ch);
> +		p->dma_write(status, CSR, ch);
>  	}
>  -	p->dma_write(status, CSR, ch);
> -
>  	if (likely(dma_chan[ch].callback != NULL))
>  		dma_chan[ch].callback(ch, status, dma_chan[ch].data);
>  -- 
> 1.7.0.4
> --
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