[PATCH] ddr: imx: Save the FW loading if it hasn't changed

[Shawn Guo]

From: Shawn Guo <shawn....@linaro.org>

Function ddr_load_train_firmware() is called 4 times in a loop by
ddr_cfg_phy(). The first 3 calls are all '1D' type and just loading the
same FWs.  Let's add a type check and save 2 of them.  This helps to
reduce DDRPHY training time from 269 ms down to 212 ms, and thus speed
up boot time ~ 50 ms.

Signed-off-by: Shawn Guo <shawn....@linaro.org>
---
 drivers/ddr/imx/phy/helper.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/ddr/imx/phy/helper.c b/drivers/ddr/imx/phy/helper.c
index e9e0294f87d3..508e1f0de34f 100644
--- a/drivers/ddr/imx/phy/helper.c
+++ b/drivers/ddr/imx/phy/helper.c
@@ -49,6 +49,13 @@ void ddr_load_train_firmware(enum fw_type type)
        unsigned long imem_start = (unsigned long)&_end + fw_offset;
        unsigned long dmem_start;
        unsigned long imem_len = IMEM_LEN, dmem_len = DMEM_LEN;
+       static enum fw_type last_type = -1;
+
+       /* If FW doesn't change, we can save the loading. */
+       if (last_type == type)
+               return;
+
+       last_type = type;
 
 #ifdef CONFIG_SPL_OF_CONTROL
        if (gd->fdt_blob && !fdt_check_header(gd->fdt_blob)) {
-- 
2.17.1