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authorGerald Kerma <drEagle@doukki.net>2014-12-13 21:35:32 +0100
committerPantelis Antoniou <pantelis.antoniou@konsulko.com>2015-01-06 10:10:04 +0200
commit28d27b79e33dea24b0fb29cf7ff6e88dfb18f030 (patch)
treef20b95f267f6f70f9c715a8b713388df7ca19fd1 /drivers
parent2591fbdba3bbae92366d0a4f20fbaf4aa0f9f65c (diff)
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MVEBUMMC : Speed up access time
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: GĂ©rald Kerma <drEagle@doukki.net> Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/mvebu_mmc.c48
1 files changed, 31 insertions, 17 deletions
diff --git a/drivers/mmc/mvebu_mmc.c b/drivers/mmc/mvebu_mmc.c
index 063d4da..91a9be0 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;