From: Keith Packard <keithp@keithp.com>
Date: Mon, 29 Apr 2013 06:06:24 +0000 (-0700)
Subject: altos: Wait after configuring boot pin before testing it
X-Git-Tag: 1.2.1~20
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=ecb128579e7576fc27c8ca93708f316b9ac91630;ds=sidebyside

altos: Wait after configuring boot pin before testing it

Clearly the pin isn't quite ready just after it's been configured, so
hang around for a while (100 nops) to let things setting down before
testing the value of the pin. Makes booting a lot more reliable.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/stm/ao_boot_pin.c b/src/stm/ao_boot_pin.c
index 03b0214f..1000a65a 100644
--- a/src/stm/ao_boot_pin.c
+++ b/src/stm/ao_boot_pin.c
@@ -31,6 +31,9 @@ ao_boot_check_pin(void)
 	ao_enable_input(&AO_BOOT_APPLICATION_GPIO, AO_BOOT_APPLICATION_PIN,
 			AO_BOOT_APPLICATION_MODE);
 
+	for (v = 0; v < 100; v++)
+		ao_arch_nop();
+
 	/* Read the value */
 	v = stm_gpio_get(&AO_BOOT_APPLICATION_GPIO, AO_BOOT_APPLICATION_PIN);