Re: [PATCH v3 4/5] clk: stm32: Fix stm32f429 ltdc driver loading hang in clk set rate. keep ltdc clk running after kernel startup
From: Stephen Boyd <sboyd@kernel.org>
Date: 2020-05-14 21:02:29
Also in:
dri-devel, linux-clk, linux-devicetree, lkml
Quoting dillon.minfei@gmail.com (2020-05-12 00:03:36)
From: dillon min <redacted> as store stm32f4_rcc_register_pll return to the wrong offset of clks,
Use () on functions, i.e. stm32f4_rcc_register_pll().
so ltdc gate clk is null. need change clks[PLL_VCO_SAI] to clks[PLL_SAI]
And quote variables like 'clks[PLL_VCO_SAI]'
add CLK_IGNORE_UNUSED for ltdc to make sure clk not be freed by clk_disable_unused
clk_disable_unused() doesn't free anything. Why does ltdc not need to be turned off if it isn't used? Is it critical to system operation? Should it be marked with the critical clk flag then? The CLK_IGNORE_UNUSED flag is almost always wrong to use.
quoted hunk ↗ jump to hunk
Signed-off-by: dillon min <redacted> --- drivers/clk/clk-stm32f4.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c index 18117ce..0ba73de 100644 --- a/drivers/clk/clk-stm32f4.c +++ b/drivers/clk/clk-stm32f4.c@@ -129,7 +129,8 @@ static const struct stm32f4_gate_data stm32f429_gates[] __initconst = { { STM32F4_RCC_APB2ENR, 20, "spi5", "apb2_div" }, { STM32F4_RCC_APB2ENR, 21, "spi6", "apb2_div" }, { STM32F4_RCC_APB2ENR, 22, "sai1", "apb2_div" }, - { STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div", + CLK_IGNORE_UNUSED }, }; static const struct stm32f4_gate_data stm32f469_gates[] __initconst = {@@ -1757,7 +1758,7 @@ static void __init stm32f4_rcc_init(struct device_node *np) clks[PLL_VCO_I2S] = stm32f4_rcc_register_pll("vco_in", &data->pll_data[1], &stm32f4_clk_lock); - clks[PLL_VCO_SAI] = stm32f4_rcc_register_pll("vco_in", + clks[PLL_SAI] = stm32f4_rcc_register_pll("vco_in", &data->pll_data[2], &stm32f4_clk_lock); for (n = 0; n < MAX_POST_DIV; n++) {
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