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| author | Nicolas Pitre <nico@cam.org> | 2006-05-05 22:32:24 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-05-05 22:32:24 +0100 |
| commit | 99532559dc7a8e686b2cef14c780a7ad5dbd4a31 (patch) | |
| tree | 3dff94d714f3e32739cd898b7eebf7910e1ef227 | |
| parent | b7d7ef87e15dea105be59ec8f14e2f92182dd421 (diff) | |
| download | linux-3.10-99532559dc7a8e686b2cef14c780a7ad5dbd4a31.tar.gz linux-3.10-99532559dc7a8e686b2cef14c780a7ad5dbd4a31.tar.bz2 linux-3.10-99532559dc7a8e686b2cef14c780a7ad5dbd4a31.zip | |
[ARM] 3500/1: fix PXA27x DMA allocation priority
Patch from Nicolas Pitre
Intel PXA27x developers manual section 5.4.1.1 lists a priority
distribution for the DMA channels differently than what the code
currently assumes. This patch fixes that.
Noticed by Simon Vogl <vogl@soft.uni-linz.ac.at>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/mach-pxa/dma.c | 17 | ||||
| -rw-r--r-- | include/asm-arm/arch-pxa/dma.h | 26 |
2 files changed, 19 insertions, 24 deletions
diff --git a/arch/arm/mach-pxa/dma.c b/arch/arm/mach-pxa/dma.c index 458112b21e2..7d8c85486c6 100644 --- a/arch/arm/mach-pxa/dma.c +++ b/arch/arm/mach-pxa/dma.c @@ -45,23 +45,16 @@ int pxa_request_dma (char *name, pxa_dma_prio prio, local_irq_save(flags); - /* try grabbing a DMA channel with the requested priority */ - for (i = prio; i < prio + PXA_DMA_NBCH(prio); i++) { - if (!dma_channels[i].name) { - found = 1; - break; - } - } - - if (!found) { - /* requested prio group is full, try hier priorities */ - for (i = prio-1; i >= 0; i--) { + do { + /* try grabbing a DMA channel with the requested priority */ + pxa_for_each_dma_prio (i, prio) { if (!dma_channels[i].name) { found = 1; break; } } - } + /* if requested prio group is full, try a hier priority */ + } while (!found && prio--); if (found) { DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR; diff --git a/include/asm-arm/arch-pxa/dma.h b/include/asm-arm/arch-pxa/dma.h index 3e88a2a02a0..a008150abc5 100644 --- a/include/asm-arm/arch-pxa/dma.h +++ b/include/asm-arm/arch-pxa/dma.h @@ -24,27 +24,29 @@ typedef struct pxa_dma_desc { volatile u32 dcmd; /* DCMD value for the current transfer */ } pxa_dma_desc; +typedef enum { + DMA_PRIO_HIGH = 0, + DMA_PRIO_MEDIUM = 1, + DMA_PRIO_LOW = 2 +} pxa_dma_prio; + #if defined(CONFIG_PXA27x) #define PXA_DMA_CHANNELS 32 -#define PXA_DMA_NBCH(prio) ((prio == DMA_PRIO_LOW) ? 16 : 8) -typedef enum { - DMA_PRIO_HIGH = 0, - DMA_PRIO_MEDIUM = 8, - DMA_PRIO_LOW = 16 -} pxa_dma_prio; +#define pxa_for_each_dma_prio(ch, prio) \ +for ( \ + ch = prio * 4; \ + ch != (4 << prio) + 16; \ + ch = (ch + 1 == (4 << prio)) ? (prio * 4 + 16) : (ch + 1) \ +) #elif defined(CONFIG_PXA25x) #define PXA_DMA_CHANNELS 16 -#define PXA_DMA_NBCH(prio) ((prio == DMA_PRIO_LOW) ? 8 : 4) -typedef enum { - DMA_PRIO_HIGH = 0, - DMA_PRIO_MEDIUM = 4, - DMA_PRIO_LOW = 8 -} pxa_dma_prio; +#define pxa_for_each_dma_prio(ch, prio) \ + for (ch = prio * 4; ch != (4 << prio); ch++) #endif |