diff options
| -rw-r--r-- | arch/arm/include/asm/arch-sunxi/mmc.h | 1 | ||||
| -rw-r--r-- | drivers/mmc/sunxi_mmc.c | 39 |
2 files changed, 32 insertions, 8 deletions
diff --git a/arch/arm/include/asm/arch-sunxi/mmc.h b/arch/arm/include/asm/arch-sunxi/mmc.h index 340e25b04d2..5daacf10eb1 100644 --- a/arch/arm/include/asm/arch-sunxi/mmc.h +++ b/arch/arm/include/asm/arch-sunxi/mmc.h @@ -119,6 +119,7 @@ struct sunxi_mmc { #define SUNXI_MMC_STATUS_CARD_PRESENT (0x1 << 8) #define SUNXI_MMC_STATUS_CARD_DATA_BUSY (0x1 << 9) #define SUNXI_MMC_STATUS_DATA_FSM_BUSY (0x1 << 10) +#define SUNXI_MMC_STATUS_FIFO_LEVEL(reg) (((reg) >> 17) & 0x3fff) #define SUNXI_MMC_NTSR_MODE_SEL_NEW (0x1 << 31) diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c index a30fd8fbdb1..115b519546e 100644 --- a/drivers/mmc/sunxi_mmc.c +++ b/drivers/mmc/sunxi_mmc.c @@ -311,8 +311,9 @@ static int mmc_trans_data_by_cpu(struct sunxi_mmc_priv *priv, struct mmc *mmc, SUNXI_MMC_STATUS_FIFO_FULL; unsigned i; unsigned *buff = (unsigned int *)(reading ? data->dest : data->src); - unsigned byte_cnt = data->blocksize * data->blocks; - unsigned timeout_msecs = byte_cnt >> 8; + unsigned word_cnt = (data->blocksize * data->blocks) >> 2; + unsigned timeout_msecs = word_cnt >> 6; + uint32_t status; unsigned long start; if (timeout_msecs < 2000) @@ -323,16 +324,38 @@ static int mmc_trans_data_by_cpu(struct sunxi_mmc_priv *priv, struct mmc *mmc, start = get_timer(0); - for (i = 0; i < (byte_cnt >> 2); i++) { - while (readl(&priv->reg->status) & status_bit) { + for (i = 0; i < word_cnt;) { + unsigned int in_fifo; + + while ((status = readl(&priv->reg->status)) & status_bit) { if (get_timer(start) > timeout_msecs) return -1; } - if (reading) - buff[i] = readl(&priv->reg->fifo); - else - writel(buff[i], &priv->reg->fifo); + /* + * For writing we do not easily know the FIFO size, so have + * to check the FIFO status after every word written. + * TODO: For optimisation we could work out a minimum FIFO + * size across all SoCs, and use that together with the current + * fill level to write chunks of words. + */ + if (!reading) { + writel(buff[i++], &priv->reg->fifo); + continue; + } + + /* + * The status register holds the current FIFO level, so we + * can be sure to collect as many words from the FIFO + * register without checking the status register after every + * read. That saves half of the costly MMIO reads, effectively + * doubling the read performance. + */ + for (in_fifo = SUNXI_MMC_STATUS_FIFO_LEVEL(status); + in_fifo > 0; + in_fifo--) + buff[i++] = readl_relaxed(&priv->reg->fifo); + dmb(); } return 0; |