omap3: nand: configurable fifo threshold to gain the throughput
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: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index fbe8414..f1648fd 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -244,7 +244,8 @@
}
/* 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)
@@ -289,7 +290,8 @@
}
/* 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)
@@ -345,8 +347,9 @@
int ret;
unsigned long tim, limit;
- /* 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;
@@ -387,7 +390,8 @@
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, 0x1, len, is_write);
if (ret)
/* PFPW engine is busy, use cpu copy method */
goto out_copy;
@@ -522,7 +526,8 @@
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 method */
goto out_copy;
@@ -569,8 +574,9 @@
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 method */
goto out_copy;