5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jernej Skrabec jernej.skrabec@gmail.com
[ 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@gmail.com Link: https://forum.libreelec.tv/thread/27295-orange-pi-3-lts-freezes/ Tested-by: Chad Wagner wagnerch42@gmail.com Reviewed-by: Chen-Yu Tsai wens@csie.org Link: https://lore.kernel.org/r/20231013181712.2128037-1-jernej.skrabec@gmail.com Signed-off-by: Jernej Skrabec jernej.skrabec@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/sunxi-ng/ccu-sun50i-h6.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
--- a/drivers/clk/sunxi-ng/ccu-sun50i-h6.c +++ b/drivers/clk/sunxi-ng/ccu-sun50i-h6.c @@ -1172,12 +1172,19 @@ 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) { struct resource *res; void __iomem *reg; + int i, ret; u32 val; - int i;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0); reg = devm_ioremap_resource(&pdev->dev, res); @@ -1231,7 +1238,15 @@ static int sun50i_h6_ccu_probe(struct pl val |= BIT(24); writel(val, reg + SUN50I_H6_HDMI_CEC_CLK_REG);
- return sunxi_ccu_probe(pdev->dev.of_node, reg, &sun50i_h6_ccu_desc); + ret = sunxi_ccu_probe(pdev->dev.of_node, 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[] = {