> -----Original Message----- > From: Tony Lindgren [mailto:tony@xxxxxxxxxxx] > Sent: Thursday, January 08, 2009 8:41 PM > To: Shilimkar, Santosh > Cc: Pandita, Vikram; linux-omap@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] [OMAPZOOM] OMAP : DMA: Spurious interrupt fix > > Hi, > > * Shilimkar, Santosh <santosh.shilimkar@xxxxxx> [081204 08:21]: > > From: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > > > > 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. Yes we need this. Actually this patch has two parts. One is the config option and another one is correcting ISR. I could have done two separate patches. --- 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); We should at least update this on mainline because this was a real issue. Reserving channel was more of a request from security drivers which also helps in this case. > > > > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > > Acked By: Nishant Kamat <nskamat@xxxxxx> > > Acked By: Gopinath Thara <thara@xxxxxx> > > --- > > --- 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 > > # > > > > -- > > To unsubscribe from this list: send the line "unsubscribe > linux-omap" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
