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....@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
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