From: Eric Anholt <eric@anholt.net>
Date: Tue, 10 May 2016 00:28:18 +0000 (-0700)
Subject: clk: bcm2835: Mark GPIO clocks enabled at boot as critical.
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~9^2~181
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=08d826625dd8a1e51414787f4e2a5c7ba0cf1a80;p=linux-4.9.git

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>
---

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 3bbd2a58db47..7040c6426e35 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1262,6 +1262,15 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
 	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 {