[PATCH 14/14] Revert "fdtdec: drop needlessly convoluted CONFIG_PHANDLE_CHECK_SEQ"

[Simon Glass]

The fdt_path_offset() function is slow since it must scan the tree.
This substantial overhead now applies to all boards.

The original code may not be ideal but it is fit for purpose and is only
needed on a few boards.

Reverting this reduces time to set up driver model by about 30ms.

Before revert:

Accumulated time:
                47,170  dm_r
                53,237  dm_spl
               572,986  dm_f

Accumulated time:
                44,598  dm_r
                50,347  dm_spl
               549,133  dm_f

This reverts commit 26f981f295d00351b6f0c69b5317b254b2361cc0.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v1:
- Add detail of impact

 configs/am65x_evm_a53_defconfig  | 1 +
 configs/evb-ast2600_defconfig    | 1 +
 configs/sama7g5ek_mmc1_defconfig | 1 +
 configs/sama7g5ek_mmc_defconfig  | 1 +
 lib/Kconfig                      | 7 +++++++
 lib/fdtdec.c                     | 7 +++++--
 6 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/configs/am65x_evm_a53_defconfig b/configs/am65x_evm_a53_defconfig
index 84ca386eafd..e4b936b6ebb 100644
--- a/configs/am65x_evm_a53_defconfig
+++ b/configs/am65x_evm_a53_defconfig
@@ -178,3 +178,4 @@ CONFIG_USB_GADGET_VENDOR_NUM=0x0451
 CONFIG_USB_GADGET_PRODUCT_NUM=0x6162
 CONFIG_USB_GADGET_DOWNLOAD=y
 CONFIG_OF_LIBFDT_OVERLAY=y
+CONFIG_PHANDLE_CHECK_SEQ=y
diff --git a/configs/evb-ast2600_defconfig b/configs/evb-ast2600_defconfig
index 11f3d57a8f4..ae84b4962a2 100644
--- a/configs/evb-ast2600_defconfig
+++ b/configs/evb-ast2600_defconfig
@@ -119,3 +119,4 @@ CONFIG_WDT=y
 CONFIG_SHA384=y
 CONFIG_HEXDUMP=y
 # CONFIG_EFI_LOADER is not set
+CONFIG_PHANDLE_CHECK_SEQ=y
diff --git a/configs/sama7g5ek_mmc1_defconfig b/configs/sama7g5ek_mmc1_defconfig
index f004e448039..ecb4dfc7854 100644
--- a/configs/sama7g5ek_mmc1_defconfig
+++ b/configs/sama7g5ek_mmc1_defconfig
@@ -79,3 +79,4 @@ CONFIG_TIMER=y
 CONFIG_MCHP_PIT64B_TIMER=y
 CONFIG_OF_LIBFDT_OVERLAY=y
 # CONFIG_EFI_LOADER_HII is not set
+CONFIG_PHANDLE_CHECK_SEQ=y
diff --git a/configs/sama7g5ek_mmc_defconfig b/configs/sama7g5ek_mmc_defconfig
index 5b42fc63f30..1d5bccd15b3 100644
--- a/configs/sama7g5ek_mmc_defconfig
+++ b/configs/sama7g5ek_mmc_defconfig
@@ -79,3 +79,4 @@ CONFIG_TIMER=y
 CONFIG_MCHP_PIT64B_TIMER=y
 CONFIG_OF_LIBFDT_OVERLAY=y
 # CONFIG_EFI_LOADER_HII is not set
+CONFIG_PHANDLE_CHECK_SEQ=y
diff --git a/lib/Kconfig b/lib/Kconfig
index 1643f7d878a..4e6c1a53da7 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -1044,6 +1044,13 @@ config LMB_RESERVED_REGIONS
 	  Define the number of supported reserved regions in the library logical
 	  memory blocks.
 
+config PHANDLE_CHECK_SEQ
+	bool "Enable phandle check while getting sequence number"
+	help
+	  When there are multiple device tree nodes with same name,
+          enable this config option to distinguish them using
+	  phandles in fdtdec_get_alias_seq() function.
+
 endmenu
 
 menu "FWU Multi Bank Updates"
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 8d5c68860ec..0827e16859f 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -519,8 +519,11 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int offset,
 		 * Adding an extra check to distinguish DT nodes with
 		 * same name
 		 */
-		if (offset != fdt_path_offset(blob, prop))
-			continue;
+		if (IS_ENABLED(CONFIG_PHANDLE_CHECK_SEQ)) {
+			if (fdt_get_phandle(blob, offset) !=
+			    fdt_get_phandle(blob, fdt_path_offset(blob, prop)))
+				continue;
+		}
 
 		val = trailing_strtol(name);
 		if (val != -1) {
-- 
2.39.0.314.g84b9a713c41-goog