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authorJohn Crispin <john@phrozen.org>2016-05-27 22:27:28 +0200
committerJohn Crispin <john@phrozen.org>2016-05-27 22:28:15 +0200
commit21802f22f06396189977f3e3b5a7103134352c15 (patch)
tree01b7852a1717725b3064060ea53f5ad093fb59ee /target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch
parent2b4e5d478b90960e35719a0262e93b35e0338b3f (diff)
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ipq806x: fix 3.18 support
accidentially removed the files in the v4.4 commit Signed-off-by: John Crispin <john@phrozen.org>
Diffstat (limited to 'target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch')
-rw-r--r--target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch55
1 files changed, 55 insertions, 0 deletions
diff --git a/target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch b/target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch
new file mode 100644
index 0000000000..29f74b760d
--- /dev/null
+++ b/target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch
@@ -0,0 +1,55 @@
+From 6793b3cd5da817c4be218bd8632f07cf4d2b0d26 Mon Sep 17 00:00:00 2001
+From: Hans de Goede <hdegoede@redhat.com>
+Date: Wed, 19 Nov 2014 14:48:59 +0100
+Subject: [PATCH] clk_mux: Fix set_parent doing the wrong thing when INDEX_BIT
+ && index >= 3
+
+If CLK_MUX_INDEX_BIT is set, then each bit turns on / off a single parent,
+so theoretically multiple parents could be enabled at the same time, but in
+practice only one bit should ever be 1. So to select parent 0, set
+the register (*) to 0x01, to select parent 1 set it 0x02, parent 2, 0x04,
+parent 3, 0x08, etc.
+
+But the current code does:
+
+ if (mux->flags & CLK_MUX_INDEX_BIT)
+ index = (1 << ffs(index));
+
+Which means that:
+
+For an input index of 0, ffs returns 0, so we set the register
+to 0x01, ok.
+
+For an input index of 1, ffs returns 1, so we set the register
+to 0x02, ok.
+
+For an input index of 2, ffs returns 2, so we set the register
+to 0x04, ok.
+
+For an input index of 3, ffs returns 1, so we set the register
+to 0x02, not good!
+
+The code should simply be:
+
+ if (mux->flags & CLK_MUX_INDEX_BIT)
+ index = 1 << index;
+
+Which always does the right thing, this commit fixes this.
+
+Signed-off-by: Hans de Goede <hdegoede@redhat.com>
+Signed-off-by: Michael Turquette <mturquette@linaro.org>
+---
+ drivers/clk/clk-mux.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/clk/clk-mux.c
++++ b/drivers/clk/clk-mux.c
+@@ -77,7 +77,7 @@ static int clk_mux_set_parent(struct clk
+
+ else {
+ if (mux->flags & CLK_MUX_INDEX_BIT)
+- index = (1 << ffs(index));
++ index = 1 << index;
+
+ if (mux->flags & CLK_MUX_INDEX_ONE)
+ index++;