diff mbox series

[U-Boot,v2,1/5] tpm: Add a delay on start-up

Message ID 20181118212228.23194-2-sjg@chromium.org
State Deferred
Delegated to: Tom Rini
Headers show
Series sandbox: Changes and improvements to support verified boot | expand

Commit Message

Simon Glass Nov. 18, 2018, 9:22 p.m. UTC 
Some TPMs hang on startup without a short delay after getting the lock.
Add a small delay to cope with this.

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

Changes in v2:
- Split out from main TPM patch

 drivers/tpm/tpm_tis_lpc.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/tpm/tpm_tis_lpc.c b/drivers/tpm/tpm_tis_lpc.c
index e993fd9f833..79e952146c2 100644
--- a/drivers/tpm/tpm_tis_lpc.c
+++ b/drivers/tpm/tpm_tis_lpc.c
@@ -408,6 +408,9 @@  static int tpm_tis_lpc_open(struct udevice *dev)
 		return ret;
 	}
 
+	/* Certain TPMs need some delay here or they hang */
+	udelay(10);
+
 	tpm_write_word(priv, TIS_STS_COMMAND_READY,
 		       &regs[locality].tpm_status);
 	return 0;