[U-Boot] [PATCH] exynos5: Don't potentially undervoltage the CPU

Sjoerd Simons sjoerd.simons at collabora.co.uk
Tue Jan 10 12:28:57 CET 2017


For snow when chainloading u-boot the CPU seems to be running at full
speed. The lower CPU voltage seems to be ok for u-boot, but when booting
linux (bringing up all cores) I'm seeing random crashes.

Bump the voltage up to a level that's safe for all cpu frequencies.

Signed-off-by: Sjoerd Simons <sjoerd.simons at collabora.co.uk>

---

 board/samsung/common/exynos5-dt.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/board/samsung/common/exynos5-dt.c b/board/samsung/common/exynos5-dt.c
index 2e3b16df45..aec1f396b0 100644
--- a/board/samsung/common/exynos5-dt.c
+++ b/board/samsung/common/exynos5-dt.c
@@ -123,13 +123,7 @@ int exynos_power_init(void)
 	if (ret)
 		return ret;
 
-	/*
-	 * This would normally be 1.3V, but since we are running slowly 1.1V
-	 * is enough. For spring it helps reduce CPU temperature and avoid
-	 * hangs with the case open. 1.1V is minimum voltage borderline for
-	 * chained bootloaders.
-	 */
-	ret = exynos_set_regulator("vdd_arm", 1100000);
+	ret = exynos_set_regulator("vdd_arm", 1300000);
 	if (ret)
 		return ret;
 	ret = exynos_set_regulator("vdd_int", 1012500);
-- 
2.11.0



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