Tony, Regarding your proposal of doing the no. of channel reservation during runtime has one problem. The whole idea was not to restrict users from using all 32 channels and hence the config option. For OMAP secure chips, few security drivers which will execute in secure contex needs dedicated DMA channels and kernel dma library can't be used in that case. So in such cases, required DMA channels can be reserved using this config option. For GP devices all 32 channels can be used currently. If it can done in better way, please suggest. Time being if needed what best I can do is, to split this patch into two parts as mentioned earlier. This will avoid confusion of spurious interrupt issue and dma channel reservation > -----Original Message----- > From: Shilimkar, Santosh > Sent: Friday, January 09, 2009 10:22 AM > To: 'Tony Lindgren' > Cc: Pandita, Vikram; linux-omap@xxxxxxxxxxxxxxx > Subject: RE: [PATCH] [OMAPZOOM] OMAP : DMA: Spurious interrupt fix > > > > -----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
