Configure the FIFO THREASHOLD value different for read and write to keep busy both filling and to drain out of FIFO at reading and writing. Signed-off-by: Sukumar Ghorai <s-ghorai@xxxxxx> Signed-off-by: Vimal Singh <vimalsingh@xxxxxx> --- arch/arm/mach-omap2/gpmc.c | 11 +++++++---- arch/arm/plat-omap/include/plat/gpmc.h | 5 ++++- drivers/mtd/nand/omap2.c | 24 +++++++++++++++--------- 3 files changed, 26 insertions(+), 14 deletions(-) diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 4e12a9f..cb38cff --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -58,7 +58,6 @@ #define GPMC_CHUNK_SHIFT 24 /* 16 MB */ #define GPMC_SECTION_SHIFT 28 /* 128 MB */ -#define PREFETCH_FIFOTHRESHOLD (0x40 << 8) #define CS_NUM_SHIFT 24 #define ENABLE_PREFETCH (0x1 << 7) #define DMA_MPU_MODE 2 @@ -538,15 +537,19 @@ EXPORT_SYMBOL(gpmc_hwcontrol); /** * gpmc_prefetch_enable - configures and starts prefetch transfer * @cs: cs (chip select) number + * @fifo_th: fifo threshold to be used for read/ write * @dma_mode: dma mode enable (1) or disable (0) * @u32_count: number of bytes to be transferred * @is_write: prefetch read(0) or write post(1) mode */ -int gpmc_prefetch_enable(int cs, int dma_mode, +int gpmc_prefetch_enable(int cs, int fifo_th, int dma_mode, unsigned int u32_count, int is_write) { - if (!(gpmc_read_reg(GPMC_PREFETCH_CONTROL))) { + if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX) { + printk(KERN_ERR "PREFETCH Fifo Threshold is not supported\n"); + return -1; + } else if (!(gpmc_read_reg(GPMC_PREFETCH_CONTROL))) { /* Set the amount of bytes to be prefetched */ gpmc_write_reg(GPMC_PREFETCH_CONFIG2, u32_count); @@ -554,7 +557,7 @@ int gpmc_prefetch_enable(int cs, int dma_mode, * enable the engine. Set which cs is has requested for. */ gpmc_write_reg(GPMC_PREFETCH_CONFIG1, ((cs << CS_NUM_SHIFT) | - PREFETCH_FIFOTHRESHOLD | + PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH | (dma_mode << DMA_MPU_MODE) | (0x1 & is_write))); diff --git a/arch/arm/plat-omap/include/plat/gpmc.h b/arch/arm/plat-omap/include/plat/gpmc.h index 4bdd851..40ce1db --- a/arch/arm/plat-omap/include/plat/gpmc.h +++ b/arch/arm/plat-omap/include/plat/gpmc.h @@ -79,6 +79,9 @@ #define GPMC_IRQ_FIFOEVENTENABLE 0x01 #define GPMC_IRQ_COUNT_EVENT 0x02 +#define PREFETCH_FIFOTHRESHOLD_MAX 0x40 +#define PREFETCH_FIFOTHRESHOLD(val) (val << 8) + /* * Note that all values in this struct are in nanoseconds, while * the register values are in gpmc_fck cycles. @@ -129,7 +132,7 @@ extern int gpmc_cs_request(int cs, unsigned long size, unsigned long *base); extern void gpmc_cs_free(int cs); extern int gpmc_cs_set_reserved(int cs, int reserved); extern int gpmc_cs_reserved(int cs); -extern int gpmc_prefetch_enable(int cs, int dma_mode, +extern int gpmc_prefetch_enable(int cs, int fifo_th, int dma_mode, unsigned int u32_count, int is_write); extern int gpmc_prefetch_reset(int cs); extern void omap3_gpmc_save_context(void); diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 2fbdd66..f136fb5 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -280,7 +280,8 @@ static void omap_read_buf_pref(struct mtd_info *mtd, u_char *buf, int len) } /* configure and start prefetch transfer */ - ret = gpmc_prefetch_enable(info->gpmc_cs, 0x0, len, 0x0); + ret = gpmc_prefetch_enable(info->gpmc_cs, + PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x0); if (ret) { /* PFPW engine is busy, use cpu copy method */ if (info->nand.options & NAND_BUSWIDTH_16) @@ -325,7 +326,8 @@ static void omap_write_buf_pref(struct mtd_info *mtd, } /* configure and start prefetch transfer */ - ret = gpmc_prefetch_enable(info->gpmc_cs, 0x0, len, 0x1); + ret = gpmc_prefetch_enable(info->gpmc_cs, + PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x1); if (ret) { /* PFPW engine is busy, use cpu copy method */ if (info->nand.options & NAND_BUSWIDTH_16) @@ -381,10 +383,11 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr, dma_addr_t dma_addr; int ret; - /* The fifo depth is 64 bytes. We have a sync at each frame and frame - * length is 64 bytes. + /* The fifo depth is 64 bytes max. + * But configure the FIFO-threahold to 32 to get a sync at each frame + * and frame length is 32 bytes. */ - int buf_len = len >> 6; + int buf_len = len >> 5; if (addr >= high_memory) { struct page *p1; @@ -423,7 +426,8 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr, OMAP24XX_DMA_GPMC, OMAP_DMA_SRC_SYNC); } /* configure and start prefetch transfer */ - ret = gpmc_prefetch_enable(info->gpmc_cs, 0x1, len, is_write); + ret = gpmc_prefetch_enable(info->gpmc_cs, + PREFETCH_FIFOTHRESHOLD_MAX/2, 0x1, len, is_write); if (ret) /* PFPW engine is busy, use cpu copy methode */ goto out_copy; @@ -570,7 +574,8 @@ static void omap_read_buf_irq_pref(struct mtd_info *mtd, u_char *buf, int len) init_completion(&info->comp); /* configure and start prefetch transfer */ - ret = gpmc_prefetch_enable(info->gpmc_cs, 0x0, len, 0x0); + ret = gpmc_prefetch_enable(info->gpmc_cs, + PREFETCH_FIFOTHRESHOLD_MAX/2, 0x0, len, 0x0); if (ret) /* PFPW engine is busy, use cpu copy methode */ goto out_copy; @@ -615,8 +620,9 @@ static void omap_write_buf_irq_pref(struct mtd_info *mtd, info->buf = (u_char *) buf; init_completion(&info->comp); - /* configure and start prefetch transfer */ - ret = gpmc_prefetch_enable(info->gpmc_cs, 0x0, len, 0x1); + /* configure and start prefetch transfer : size=24 */ + ret = gpmc_prefetch_enable(info->gpmc_cs, + (PREFETCH_FIFOTHRESHOLD_MAX*3)/8, 0x0, len, 0x1); if (ret) /* PFPW engine is busy, use cpu copy methode */ goto out_copy; -- 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