openwrtv3/target/linux/brcm2708/patches-4.9/950-0021-clk-bcm2835-Mark-GPIO-clocks-enabled-at-boot-as-crit.patch

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From 599e7165ec6477139dae4f32a12e8d49d5dd8859 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Mon, 9 May 2016 17:28:18 -0700
Subject: [PATCH] clk: bcm2835: Mark GPIO clocks enabled at boot as critical.
These divide off of PLLD_PER and are used for the ethernet and wifi
PHYs source PLLs. Neither of them is currently represented by a phy
device that would grab the clock for us.
This keeps other drivers from killing the networking PHYs when they
disable their own clocks and trigger PLLD_PER's refcount going to 0.
v2: Skip marking as critical if they aren't on at boot.
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/clk/bcm/clk-bcm2835.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1268,6 +1268,15 @@ static struct clk_hw *bcm2835_register_c
init.name = data->name;
init.flags = data->flags | CLK_IGNORE_UNUSED;
+ /*
+ * Some GPIO clocks for ethernet/wifi PLLs are marked as
+ * critical (since some platforms use them), but if the
+ * firmware didn't have them turned on then they clearly
+ * aren't actually critical.
+ */
+ if ((cprman_read(cprman, data->ctl_reg) & CM_ENABLE) == 0)
+ init.flags &= ~CLK_IS_CRITICAL;
+
if (data->is_vpu_clock) {
init.ops = &bcm2835_vpu_clock_clk_ops;
} else {