MVEBUMMC : Speed up access time
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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 <drEagle@doukki.net>
Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
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 @@
#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_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 @@
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 @@
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 @@
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 28d98fe..7fb71f7 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 | \