This is a note to let you know that I've just added the patch titled
clk: sunxi-ng: a31: Fix CLK_OUT_* clock ops
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: clk-sunxi-ng-a31-fix-clk_out_-clock-ops.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 5682e268350f9eccdbb04006605c1b7068a7b323 Mon Sep 17 00:00:00 2001
From: Chen-Yu Tsai wens@csie.org Date: Sat, 17 Feb 2018 21:05:04 +0800 Subject: clk: sunxi-ng: a31: Fix CLK_OUT_* clock ops
From: Chen-Yu Tsai wens@csie.org
commit 5682e268350f9eccdbb04006605c1b7068a7b323 upstream.
When support for the A31/A31s CCU was first added, the clock ops for the CLK_OUT_* clocks was set to the wrong type. The clocks are MP-type, but the ops was set for div (M) clocks. This went unnoticed until now. This was because while they are different clocks, their data structures aligned in a way that ccu_div_ops would access the second ccu_div_internal and ccu_mux_internal structures, which were valid, if not incorrect.
Furthermore, the use of these CLK_OUT_* was for feeding a precise 32.768 kHz clock signal to the WiFi chip. This was achievable by using the parent with the same clock rate and no divider. So the incorrect divider setting did not affect this usage.
Commit 946797aa3f08 ("clk: sunxi-ng: Support fixed post-dividers on MP style clocks") added a new field to the ccu_mp structure, which broke the aforementioned alignment. Now the system crashes as div_ops tries to look up a nonexistent table.
Reported-by: Philipp Rossak embed3d@gmail.com Tested-by: Philipp Rossak embed3d@gmail.com Fixes: c6e6c96d8fa6 ("clk: sunxi-ng: Add A31/A31s clocks") Cc: stable@vger.kernel.org Signed-off-by: Chen-Yu Tsai wens@csie.org Signed-off-by: Maxime Ripard maxime.ripard@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/clk/sunxi-ng/ccu-sun6i-a31.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/clk/sunxi-ng/ccu-sun6i-a31.c +++ b/drivers/clk/sunxi-ng/ccu-sun6i-a31.c @@ -750,7 +750,7 @@ static struct ccu_mp out_a_clk = { .features = CCU_FEATURE_FIXED_PREDIV, .hw.init = CLK_HW_INIT_PARENTS("out-a", clk_out_parents, - &ccu_div_ops, + &ccu_mp_ops, 0), }, }; @@ -771,7 +771,7 @@ static struct ccu_mp out_b_clk = { .features = CCU_FEATURE_FIXED_PREDIV, .hw.init = CLK_HW_INIT_PARENTS("out-b", clk_out_parents, - &ccu_div_ops, + &ccu_mp_ops, 0), }, }; @@ -792,7 +792,7 @@ static struct ccu_mp out_c_clk = { .features = CCU_FEATURE_FIXED_PREDIV, .hw.init = CLK_HW_INIT_PARENTS("out-c", clk_out_parents, - &ccu_div_ops, + &ccu_mp_ops, 0), }, };
Patches currently in stable-queue which might be from wens@csie.org are
queue-4.9/clk-sunxi-ng-a31-fix-clk_out_-clock-ops.patch