From 716ca530e1c4515d8683c9d5be3d56b301758b66 Mon Sep 17 00:00:00 2001 From: James <> Date: Wed, 4 Nov 2015 11:49:21 +0000 Subject: trunk-47381 --- ...-set_parent-doing-the-wrong-thing-when-IN.patch | 55 ++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch (limited to 'target/linux/ipq806x/patches-3.18/130-clk_mux-Fix-set_parent-doing-the-wrong-thing-when-IN.patch') 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 0000000..29f74b7 --- /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 +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 +Signed-off-by: Michael Turquette +--- + 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++; -- cgit v1.2.3