This is a note to let you know that I've just added the patch titled
clk: sunxi-ng: h6: Reparent CPUX during PLL CPUX rate change
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
clk-sunxi-ng-h6-reparent-cpux-during-pll-cpux-rate-c.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 980e6690947bc799e2e649a20f956cf5d65e7306
Author: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Date: Fri Oct 13 20:17:12 2023 +0200
clk: sunxi-ng: h6: Reparent CPUX during PLL CPUX rate change
[ Upstream commit 7e91ed763dc07437777bd012af7a2bd4493731ff ]
While PLL CPUX clock rate change when CPU is running from it works in
vast majority of cases, now and then it causes instability. This leads
to system crashes and other undefined behaviour. After a lot of testing
(30+ hours) while also doing a lot of frequency switches, we can't
observe any instability issues anymore when doing reparenting to stable
clock like 24 MHz oscillator.
Fixes: 524353ea480b ("clk: sunxi-ng: add support for the Allwinner H6 CCU")
Reported-by: Chad Wagner <wagnerch42@xxxxxxxxx>
Link: https://forum.libreelec.tv/thread/27295-orange-pi-3-lts-freezes/
Tested-by: Chad Wagner <wagnerch42@xxxxxxxxx>
Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxx>
Link: https://lore.kernel.org/r/20231013181712.2128037-1-jernej.skrabec@xxxxxxxxx
Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c
index 42568c6161814..892df807275c8 100644
--- a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c
+++ b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c
@@ -1181,11 +1181,18 @@ static const u32 usb2_clk_regs[] = {
SUN50I_H6_USB3_CLK_REG,
};
+static struct ccu_mux_nb sun50i_h6_cpu_nb = {
+ .common = &cpux_clk.common,
+ .cm = &cpux_clk.mux,
+ .delay_us = 1,
+ .bypass_index = 0, /* index of 24 MHz oscillator */
+};
+
static int sun50i_h6_ccu_probe(struct platform_device *pdev)
{
void __iomem *reg;
+ int i, ret;
u32 val;
- int i;
reg = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(reg))
@@ -1252,7 +1259,15 @@ static int sun50i_h6_ccu_probe(struct platform_device *pdev)
val |= BIT(24);
writel(val, reg + SUN50I_H6_HDMI_CEC_CLK_REG);
- return devm_sunxi_ccu_probe(&pdev->dev, reg, &sun50i_h6_ccu_desc);
+ ret = devm_sunxi_ccu_probe(&pdev->dev, reg, &sun50i_h6_ccu_desc);
+ if (ret)
+ return ret;
+
+ /* Reparent CPU during PLL CPUX rate changes */
+ ccu_mux_notifier_register(pll_cpux_clk.common.hw.clk,
+ &sun50i_h6_cpu_nb);
+
+ return 0;
}
static const struct of_device_id sun50i_h6_ccu_ids[] = {
