From ca54d06fcacfdeb0b07acb4c6469a96fb02a9b44 Mon Sep 17 00:00:00 2001 From: Aidan MacDonald Date: Thu, 28 Apr 2022 17:44:53 +0100 Subject: [PATCH] clk: ingenic: Mark critical clocks in Ingenic SoCs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Consider CPU, L2 cache, and memory clocks as critical to prevent them -- and the parent clocks -- from being automatically gated, since nothing calls clk_get() on these clocks. Gating the CPU clock hangs the processor, and gating memory makes external DRAM inaccessible. Normal kernel code can't hope to deal with either situation so those clocks have to be critical. The L2 cache is required only if caches are running, and could be gated if the kernel takes care to flush and disable caches before gating the clock. There's no mechanism to do this, and probably no reason to do it, so it's simpler to mark the L2 cache as critical. Signed-off-by: Aidan MacDonald Reviewed-by: Paul Cercueil Link: https://lore.kernel.org/r/20220428164454.17908-3-aidanmacdonald.0x0@gmail.com Tested-by: 周琰杰 (Zhou Yanjie) # On X1000 and X1830 Signed-off-by: Stephen Boyd --- drivers/clk/ingenic/jz4725b-cgu.c | 10 ++++++++++ drivers/clk/ingenic/jz4740-cgu.c | 10 ++++++++++ drivers/clk/ingenic/jz4760-cgu.c | 10 ++++++++++ drivers/clk/ingenic/jz4770-cgu.c | 5 +++++ drivers/clk/ingenic/jz4780-cgu.c | 15 +++++++++++++++ drivers/clk/ingenic/x1000-cgu.c | 15 +++++++++++++++ drivers/clk/ingenic/x1830-cgu.c | 11 +++++++++++ 7 files changed, 76 insertions(+) diff --git a/drivers/clk/ingenic/jz4725b-cgu.c b/drivers/clk/ingenic/jz4725b-cgu.c index 15d6179..590e9c85 100644 --- a/drivers/clk/ingenic/jz4725b-cgu.c +++ b/drivers/clk/ingenic/jz4725b-cgu.c @@ -87,6 +87,11 @@ static const struct ingenic_cgu_clk_info jz4725b_cgu_clocks[] = { [JZ4725B_CLK_CCLK] = { "cclk", CGU_CLK_DIV, + /* + * Disabling the CPU clock or any parent clocks will hang the + * system; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4725B_CLK_PLL, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1, 0, @@ -114,6 +119,11 @@ static const struct ingenic_cgu_clk_info jz4725b_cgu_clocks[] = { [JZ4725B_CLK_MCLK] = { "mclk", CGU_CLK_DIV, + /* + * Disabling MCLK or its parents will render DRAM + * inaccessible; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4725B_CLK_PLL, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 12, 1, 4, 22, -1, -1, 0, diff --git a/drivers/clk/ingenic/jz4740-cgu.c b/drivers/clk/ingenic/jz4740-cgu.c index 43ffb62..3e0a305 100644 --- a/drivers/clk/ingenic/jz4740-cgu.c +++ b/drivers/clk/ingenic/jz4740-cgu.c @@ -102,6 +102,11 @@ static const struct ingenic_cgu_clk_info jz4740_cgu_clocks[] = { [JZ4740_CLK_CCLK] = { "cclk", CGU_CLK_DIV, + /* + * Disabling the CPU clock or any parent clocks will hang the + * system; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4740_CLK_PLL, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1, 0, @@ -129,6 +134,11 @@ static const struct ingenic_cgu_clk_info jz4740_cgu_clocks[] = { [JZ4740_CLK_MCLK] = { "mclk", CGU_CLK_DIV, + /* + * Disabling MCLK or its parents will render DRAM + * inaccessible; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4740_CLK_PLL, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 12, 1, 4, 22, -1, -1, 0, diff --git a/drivers/clk/ingenic/jz4760-cgu.c b/drivers/clk/ingenic/jz4760-cgu.c index 8fdd383..ecd395a 100644 --- a/drivers/clk/ingenic/jz4760-cgu.c +++ b/drivers/clk/ingenic/jz4760-cgu.c @@ -143,6 +143,11 @@ static const struct ingenic_cgu_clk_info jz4760_cgu_clocks[] = { [JZ4760_CLK_CCLK] = { "cclk", CGU_CLK_DIV, + /* + * Disabling the CPU clock or any parent clocks will hang the + * system; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4760_CLK_PLL0, }, .div = { CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1, 0, @@ -175,6 +180,11 @@ static const struct ingenic_cgu_clk_info jz4760_cgu_clocks[] = { }, [JZ4760_CLK_MCLK] = { "mclk", CGU_CLK_DIV, + /* + * Disabling MCLK or its parents will render DRAM + * inaccessible; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4760_CLK_PLL0, }, .div = { CGU_REG_CPCCR, 12, 1, 4, 22, -1, -1, 0, diff --git a/drivers/clk/ingenic/jz4770-cgu.c b/drivers/clk/ingenic/jz4770-cgu.c index 7ef9125..6ae1740 100644 --- a/drivers/clk/ingenic/jz4770-cgu.c +++ b/drivers/clk/ingenic/jz4770-cgu.c @@ -149,6 +149,11 @@ static const struct ingenic_cgu_clk_info jz4770_cgu_clocks[] = { [JZ4770_CLK_CCLK] = { "cclk", CGU_CLK_DIV, + /* + * Disabling the CPU clock or any parent clocks will hang the + * system; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4770_CLK_PLL0, }, .div = { CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1, 0, diff --git a/drivers/clk/ingenic/jz4780-cgu.c b/drivers/clk/ingenic/jz4780-cgu.c index e357c22..b1dadc0 100644 --- a/drivers/clk/ingenic/jz4780-cgu.c +++ b/drivers/clk/ingenic/jz4780-cgu.c @@ -341,12 +341,22 @@ static const struct ingenic_cgu_clk_info jz4780_cgu_clocks[] = { [JZ4780_CLK_CPU] = { "cpu", CGU_CLK_DIV, + /* + * Disabling the CPU clock or any parent clocks will hang the + * system; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4780_CLK_CPUMUX, -1, -1, -1 }, .div = { CGU_REG_CLOCKCONTROL, 0, 1, 4, 22, -1, -1 }, }, [JZ4780_CLK_L2CACHE] = { "l2cache", CGU_CLK_DIV, + /* + * The L2 cache clock is critical if caches are enabled and + * disabling it or any parent clocks will hang the system. + */ + .flags = CLK_IS_CRITICAL, .parents = { JZ4780_CLK_CPUMUX, -1, -1, -1 }, .div = { CGU_REG_CLOCKCONTROL, 4, 1, 4, -1, -1, -1 }, }, @@ -380,6 +390,11 @@ static const struct ingenic_cgu_clk_info jz4780_cgu_clocks[] = { [JZ4780_CLK_DDR] = { "ddr", CGU_CLK_MUX | CGU_CLK_DIV, + /* + * Disabling DDR clock or its parents will render DRAM + * inaccessible; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { -1, JZ4780_CLK_SCLKA, JZ4780_CLK_MPLL, -1 }, .mux = { CGU_REG_DDRCDR, 30, 2 }, .div = { CGU_REG_DDRCDR, 0, 1, 4, 29, 28, 27 }, diff --git a/drivers/clk/ingenic/x1000-cgu.c b/drivers/clk/ingenic/x1000-cgu.c index 3c4d5a7..b2ce3fb 100644 --- a/drivers/clk/ingenic/x1000-cgu.c +++ b/drivers/clk/ingenic/x1000-cgu.c @@ -251,6 +251,11 @@ static const struct ingenic_cgu_clk_info x1000_cgu_clocks[] = { [X1000_CLK_CPU] = { "cpu", CGU_CLK_DIV | CGU_CLK_GATE, + /* + * Disabling the CPU clock or any parent clocks will hang the + * system; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { X1000_CLK_CPUMUX, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1 }, .gate = { CGU_REG_CLKGR, 30 }, @@ -258,6 +263,11 @@ static const struct ingenic_cgu_clk_info x1000_cgu_clocks[] = { [X1000_CLK_L2CACHE] = { "l2cache", CGU_CLK_DIV, + /* + * The L2 cache clock is critical if caches are enabled and + * disabling it or any parent clocks will hang the system. + */ + .flags = CLK_IS_CRITICAL, .parents = { X1000_CLK_CPUMUX, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 4, 1, 4, 22, -1, -1 }, }, @@ -290,6 +300,11 @@ static const struct ingenic_cgu_clk_info x1000_cgu_clocks[] = { [X1000_CLK_DDR] = { "ddr", CGU_CLK_MUX | CGU_CLK_DIV | CGU_CLK_GATE, + /* + * Disabling DDR clock or its parents will render DRAM + * inaccessible; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { -1, X1000_CLK_SCLKA, X1000_CLK_MPLL, -1 }, .mux = { CGU_REG_DDRCDR, 30, 2 }, .div = { CGU_REG_DDRCDR, 0, 1, 4, 29, 28, 27 }, diff --git a/drivers/clk/ingenic/x1830-cgu.c b/drivers/clk/ingenic/x1830-cgu.c index e01ec2d..0fd46e5 100644 --- a/drivers/clk/ingenic/x1830-cgu.c +++ b/drivers/clk/ingenic/x1830-cgu.c @@ -225,6 +225,7 @@ static const struct ingenic_cgu_clk_info x1830_cgu_clocks[] = { [X1830_CLK_CPU] = { "cpu", CGU_CLK_DIV | CGU_CLK_GATE, + .flags = CLK_IS_CRITICAL, .parents = { X1830_CLK_CPUMUX, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 0, 1, 4, 22, -1, -1 }, .gate = { CGU_REG_CLKGR1, 15 }, @@ -232,6 +233,11 @@ static const struct ingenic_cgu_clk_info x1830_cgu_clocks[] = { [X1830_CLK_L2CACHE] = { "l2cache", CGU_CLK_DIV, + /* + * The L2 cache clock is critical if caches are enabled and + * disabling it or any parent clocks will hang the system. + */ + .flags = CLK_IS_CRITICAL, .parents = { X1830_CLK_CPUMUX, -1, -1, -1 }, .div = { CGU_REG_CPCCR, 4, 1, 4, 22, -1, -1 }, }, @@ -264,6 +270,11 @@ static const struct ingenic_cgu_clk_info x1830_cgu_clocks[] = { [X1830_CLK_DDR] = { "ddr", CGU_CLK_MUX | CGU_CLK_DIV | CGU_CLK_GATE, + /* + * Disabling DDR clock or its parents will render DRAM + * inaccessible; mark it critical. + */ + .flags = CLK_IS_CRITICAL, .parents = { -1, X1830_CLK_SCLKA, X1830_CLK_MPLL, -1 }, .mux = { CGU_REG_DDRCDR, 30, 2 }, .div = { CGU_REG_DDRCDR, 0, 1, 4, 29, 28, 27 }, -- 2.7.4