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

From: dillon . minfei
Date: Fri May 14 2021 - 07:02:58 EST


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 },
};

--
2.7.4