From 28d27b79e33dea24b0fb29cf7ff6e88dfb18f030 Mon Sep 17 00:00:00 2001 From: Gerald Kerma Date: Sat, 13 Dec 2014 21:35:32 +0100 Subject: [PATCH] MVEBUMMC : Speed up access time MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Get about 40x faster access on SHEEVAPLUG MMC Fix some SD type compatibility Changes in v3: - fix the HW_STATE (from linux mvsdio) - review delays and timeouts Changes in v2: - increase number of loops - remove initial delay Changes in v1: - review all loops, delays and timeouts Signed-off-by: Gérald Kerma Acked-by: Pantelis Antoniou --- drivers/mmc/mvebu_mmc.c | 48 ++++++++++++++++++++++++++--------------- include/mvebu_mmc.h | 1 + 2 files changed, 32 insertions(+), 17 deletions(-) diff --git a/drivers/mmc/mvebu_mmc.c b/drivers/mmc/mvebu_mmc.c index 063d4dacbc..91a9be06e6 100644 --- a/drivers/mmc/mvebu_mmc.c +++ b/drivers/mmc/mvebu_mmc.c @@ -23,6 +23,8 @@ DECLARE_GLOBAL_DATA_PTR; #define MVEBU_TARGET_DRAM 0 +#define TIMEOUT_DELAY 5*CONFIG_SYS_HZ /* wait 5 seconds */ + static void mvebu_mmc_write(u32 offs, u32 val) { writel(val, CONFIG_SYS_MMC_BASE + (offs)); @@ -63,7 +65,7 @@ static int mvebu_mmc_setup_data(struct mmc_data *data) static int mvebu_mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data) { - int timeout = 10; + ulong start; ushort waittype = 0; ushort resptype = 0; ushort xfertype = 0; @@ -72,19 +74,33 @@ static int mvebu_mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, debug("cmdidx [0x%x] resp_type[0x%x] cmdarg[0x%x]\n", cmd->cmdidx, cmd->resp_type, cmd->cmdarg); - udelay(10*1000); - debug("%s: cmd %d (hw state 0x%04x)\n", DRIVER_NAME, cmd->cmdidx, mvebu_mmc_read(SDIO_HW_STATE)); - /* Checking if card is busy */ - while ((mvebu_mmc_read(SDIO_HW_STATE) & CARD_BUSY)) { - if (timeout == 0) { - printf("%s: card busy!\n", DRIVER_NAME); - return -1; - } - timeout--; - udelay(1000); + /* + * Hardware weirdness. The FIFO_EMPTY bit of the HW_STATE + * register is sometimes not set before a while when some + * "unusual" data block sizes are used (such as with the SWITCH + * command), even despite the fact that the XFER_DONE interrupt + * was raised. And if another data transfer starts before + * this bit comes to good sense (which eventually happens by + * itself) then the new transfer simply fails with a timeout. + */ + if (!(mvebu_mmc_read(SDIO_HW_STATE) & CMD_FIFO_EMPTY)) { + ushort hw_state, count = 0; + + start = get_timer(0); + do { + hw_state = mvebu_mmc_read(SDIO_HW_STATE); + if ((get_timer(0) - start) > TIMEOUT_DELAY) { + printf("%s : FIFO_EMPTY bit missing\n", + DRIVER_NAME); + break; + } + count++; + } while (!(hw_state & CMD_FIFO_EMPTY)); + debug("%s *** wait for FIFO_EMPTY bit (hw=0x%04x, count=%d, jiffies=%ld)\n", + DRIVER_NAME, hw_state, count, (get_timer(0) - (start))); } /* Set up for a data transfer if we have one */ @@ -147,8 +163,7 @@ static int mvebu_mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, mvebu_mmc_write(SDIO_NOR_INTR_EN, SDIO_POLL_MASK); mvebu_mmc_write(SDIO_ERR_INTR_EN, SDIO_POLL_MASK); - /* Waiting for completion */ - timeout = 1000000; + start = get_timer(0); while (!((mvebu_mmc_read(SDIO_NOR_INTR_STATUS)) & waittype)) { if (mvebu_mmc_read(SDIO_NOR_INTR_STATUS) & SDIO_NOR_ERROR) { @@ -161,13 +176,12 @@ static int mvebu_mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, return COMM_ERR; } - timeout--; - udelay(1); - if (timeout <= 0) { - printf("%s: command timed out\n", DRIVER_NAME); + if ((get_timer(0) - start) > TIMEOUT_DELAY) { + debug("%s: command timed out\n", DRIVER_NAME); return TIMEOUT; } } + if (mvebu_mmc_read(SDIO_ERR_INTR_STATUS) & (SDIO_ERR_CMD_TIMEOUT | SDIO_ERR_DATA_TIMEOUT)) return TIMEOUT; diff --git a/include/mvebu_mmc.h b/include/mvebu_mmc.h index 28d98fe148..7fb71f7219 100644 --- a/include/mvebu_mmc.h +++ b/include/mvebu_mmc.h @@ -79,6 +79,7 @@ #define CMD_INHIBIT (1 << 0) #define CMD_TXACTIVE (1 << 8) #define CMD_RXACTIVE (1 << 9) +#define CMD_FIFO_EMPTY (1 << 13) #define CMD_AUTOCMD12ACTIVE (1 << 14) #define CMD_BUS_BUSY (CMD_AUTOCMD12ACTIVE | \ CMD_RXACTIVE | \ -- 2.25.1