[U-Boot] [PATCH 13/13] bootcount: i2c: Delay after writing

[Ian Ray]

Since 2018.11, the pattern of bootcount load and store has changed such
that bootcount_inc() and bootcount_error() will load, increment, store,
and load *again*.  The second load exposes a timing problem whereby the
i2c read fails.  The root cause _seems_ to relate to performance of the
24c08 EEPROM.  Insert a delay after writing to work around this.

Signed-off-by: Ian Ray <ian.ray at ge.com>
---
 drivers/bootcount/bootcount_i2c.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/bootcount/bootcount_i2c.c b/drivers/bootcount/bootcount_i2c.c
index ed22389..dd86426 100644
--- a/drivers/bootcount/bootcount_i2c.c
+++ b/drivers/bootcount/bootcount_i2c.c
@@ -64,6 +64,10 @@ void bootcount_store(ulong a)
 			CONFIG_BOOTCOUNT_ALEN, buf, sizeof(buf));
 	if (ret != 0)
 		puts("Error writing bootcount\n");
+	else
+		/* Datasheet claims 2 ms typical write cycle time.
+		 * This delay ensures that next read will succeed. */
+		mdelay(5);
 
 	bootcount_set_bus_back(prev_i2c_bus);
 }
-- 
2.10.1