Re: [PATCH 3/4] clk: stm32: Fix stm32f429's ltdc driver hang in set clock rate

[Patrice CHOTARD]

Hi Dillon

On 5/14/21 1:02 PM, dillon.minfei@xxxxxxxxx wrote:
> From: Dillon Min <dillon.minfei@xxxxxxxxx>
> 
> This is due to misuse ‘PLL_VCO_SAI' and'PLL_SAI' in clk-stm32f4.c
> 'PLL_SAI' is 2, 'PLL_VCO_SAI' is 7(defined in
> include/dt-bindings/clock/stm32fx-clock.h).
> 
> 'post_div' point to 'post_div_data[]', 'post_div->pll_num'
> is PLL_I2S or PLL_SAI.
> 
> 'clks[PLL_VCO_SAI]' has valid 'struct clk_hw* ' return
> from stm32f4_rcc_register_pll() but, at line 1777 of
> driver/clk/clk-stm32f4.c, use the 'clks[post_div->pll_num]',
> equal to 'clks[PLL_SAI]', this is invalid array member at that time.
> 
> Fixes: 517633ef630e ("clk: stm32f4: Add post divisor for I2S & SAI PLLs")
> Signed-off-by: Dillon Min <dillon.minfei@xxxxxxxxx>
> Acked-by: Stephen Boyd <sboyd@xxxxxxxxxx>
> Link: https://lore.kernel.org/linux-arm-kernel/1590564453-24499-6-git-send-email-dillon.minfei@xxxxxxxxx/
> ---
>  drivers/clk/clk-stm32f4.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
> index 18117ce5ff85..42ca2dd86aea 100644
> --- a/drivers/clk/clk-stm32f4.c
> +++ b/drivers/clk/clk-stm32f4.c
> @@ -557,13 +557,13 @@ static const struct clk_div_table post_divr_table[] = {
>  
>  #define MAX_POST_DIV 3
>  static const struct stm32f4_pll_post_div_data  post_div_data[MAX_POST_DIV] = {
> -	{ CLK_I2SQ_PDIV, PLL_I2S, "plli2s-q-div", "plli2s-q",
> +	{ CLK_I2SQ_PDIV, PLL_VCO_I2S, "plli2s-q-div", "plli2s-q",
>  		CLK_SET_RATE_PARENT, STM32F4_RCC_DCKCFGR, 0, 5, 0, NULL},
>  
> -	{ CLK_SAIQ_PDIV, PLL_SAI, "pllsai-q-div", "pllsai-q",
> +	{ CLK_SAIQ_PDIV, PLL_VCO_SAI, "pllsai-q-div", "pllsai-q",
>  		CLK_SET_RATE_PARENT, STM32F4_RCC_DCKCFGR, 8, 5, 0, NULL },
>  
> -	{ NO_IDX, PLL_SAI, "pllsai-r-div", "pllsai-r", CLK_SET_RATE_PARENT,
> +	{ NO_IDX, PLL_VCO_SAI, "pllsai-r-div", "pllsai-r", CLK_SET_RATE_PARENT,
>  		STM32F4_RCC_DCKCFGR, 16, 2, 0, post_divr_table },
>  };
>  
> 
Reviewed-by: Patrice Chotard <patrice.chotard@xxxxxxxxxxx>

Thanks
Patrice