Re: [PATCH] [OMAPZOOM] OMAP : DMA: Spurious interrupt fix

[Tony Lindgren <tony@atomide.com>]

Hi,

* Shilimkar, Santosh <santosh.shilimkar@ti.com> [081204 08:21]:
> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
> 
> This fixes the spurious interrupt issue on a DMA channel. 

Sounds like we need to do this. But let's rather do it during runtime
in dma init with cpu_is_omapXXXX() and omap_type() macros.

Regards,

Tony



> 
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Acked By: Nishant Kamat <nskamat@ti.com>
> Acked By: Gopinath Thara <thara@ti.com>
> ---
> --- omapkernel.orig/arch/arm/plat-omap/include/mach/dma.h	2008-12-04 10:29:08.949018434 +0530
> +++ omapkernel/arch/arm/plat-omap/include/mach/dma.h	2008-12-04 11:14:25.359087775 +0530
> @@ -67,7 +67,11 @@
>  #define OMAP_DMA4_CAPS_4		0x74
>  
>  #define OMAP1_LOGICAL_DMA_CH_COUNT	17
> +#ifdef CONFIG_OMAP_DMA_LIBRARY_CHANNELS
> +#define OMAP_DMA4_LOGICAL_DMA_CH_COUNT	CONFIG_OMAP_DMA_LIBRARY_CHANNELS
> +#else
>  #define OMAP_DMA4_LOGICAL_DMA_CH_COUNT	32	/* REVISIT: Is this 32 + 2? */
> +#endif
>  
>  /* Common channel specific registers for omap1 */
>  #define OMAP1_DMA_CH_BASE(n)		(0x40 * (n) + 0x00)
> Index: omapkernel/arch/arm/plat-omap/Kconfig
> ===================================================================
> --- omapkernel.orig/arch/arm/plat-omap/Kconfig	2008-12-04 10:29:08.949018434 +0530
> +++ omapkernel/arch/arm/plat-omap/Kconfig	2008-12-04 10:38:21.883850512 +0530
> @@ -256,6 +256,18 @@ config OMAP_SERIAL_WAKE
>  	  to data on the serial RX line. This allows you to wake the
>  	  system from serial console.
>  
> +
> +config OMAP_DMA_LIBRARY_CHANNELS
> +        int "DMA channels controlled by the kernel DMA library"
> +        range 24 32
> +        depends on ARCH_OMAP3
> +        default "32"
> +        help
> +          Some of the OMAP System DMA channels may need to be
> +          reserved for software that don't use the DMA library, such as
> +          security drivers. Use this option to limit the number of channels
> +          controlled by the kernel DMA library.
> +
>  endmenu
>  
>  endif
> Index: omapkernel/arch/arm/configs/omap_3430sdp_defconfig
> ===================================================================
> --- omapkernel.orig/arch/arm/configs/omap_3430sdp_defconfig	2008-12-04 10:29:08.949018434 +0530
> +++ omapkernel/arch/arm/configs/omap_3430sdp_defconfig	2008-12-04 10:38:21.884850481 +0530
> @@ -177,7 +177,7 @@ CONFIG_ARCH_OMAP_OTG=y
>  # CONFIG_ARCH_OMAP1 is not set
>  # CONFIG_ARCH_OMAP2 is not set
>  CONFIG_ARCH_OMAP3=y
> -
> +CONFIG_OMAP_DMA_LIBRARY_CHANNELS=24
>  #
>  # OMAP Feature Selections
>  #
> Index: omapkernel/arch/arm/plat-omap/dma.c
> ===================================================================
> --- omapkernel.orig/arch/arm/plat-omap/dma.c	2008-12-04 10:38:16.732010840 +0530
> +++ omapkernel/arch/arm/plat-omap/dma.c	2008-12-04 11:11:07.671274902 +0530
> @@ -1946,7 +1946,7 @@ static int omap2_dma_handle_ch(int ch)
>  /* STATUS register count is from 1-32 while our is 0-31 */
>  static irqreturn_t omap2_dma_irq_handler(int irq, void *dev_id)
>  {
> -	u32 val;
> +	u32 val, enable_reg;
>  	int i;
>  
>  	val = dma_read(IRQSTATUS_L0);
> @@ -1955,6 +1955,8 @@ static irqreturn_t omap2_dma_irq_handler
>  			printk(KERN_WARNING "Spurious DMA IRQ\n");
>  		return IRQ_HANDLED;
>  	}
> +	enable_reg = dma_read(IRQENABLE_L0);
> +	val &= enable_reg; /* Dispatch only relevant interrupts */
>  	for (i = 0; i < dma_lch_count && val != 0; i++) {
>  		if (val & 1)
>  			omap2_dma_handle_ch(i);
> Index: omapkernel/arch/arm/configs/omap_ldp_defconfig
> ===================================================================
> --- omapkernel.orig/arch/arm/configs/omap_ldp_defconfig	2008-12-04 11:18:54.000000000 +0530
> +++ omapkernel/arch/arm/configs/omap_ldp_defconfig	2008-12-04 11:19:33.507466484 +0530
> @@ -177,6 +177,7 @@ CONFIG_ARCH_OMAP_OTG=y
>  # CONFIG_ARCH_OMAP1 is not set
>  # CONFIG_ARCH_OMAP2 is not set
>  CONFIG_ARCH_OMAP3=y
> +CONFIG_OMAP_DMA_LIBRARY_CHANNELS=32
>  #
>  # OMAP Feature Selections
>  #
> 
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