[PATCH] clk: qcom: apss-ipq-pll: use stromer ops for IPQ5018 to fix boot failure

From: Gabor Juhos
Date: Mon Mar 11 2024 - 11:06:57 EST


Booting v6.8 results in a hang on various IPQ5018 based boards.
Investigating the problem showed that the hang happens when the
clk_alpha_pll_stromer_plus_set_rate() function tries to write
into the PLL_MODE register of the APSS PLL.

Checking the downstream code revealed that it uses [1] stromer
specific operations for IPQ5018, whereas in the current code
the stromer plus specific operations are used.

The ops in the 'ipq_pll_stromer_plus' clock definition can't be
changed since that is needed for IPQ5332, so add a new alpha pll
clock declaration which uses the correct stromer ops and use this
new clock for IPQ5018 to avoid the boot failure.

1. https://git.codelinaro.org/clo/qsdk/oss/kernel/linux-ipq-5.4/-/blob/NHSS.QSDK.12.4/drivers/clk/qcom/apss-ipq5018.c#L67

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 50492f929486 ("clk: qcom: apss-ipq-pll: add support for IPQ5018")
Signed-off-by: Gabor Juhos <j4g8y7@xxxxxxxxx>
---
Based on v6.8.
---
drivers/clk/qcom/apss-ipq-pll.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/apss-ipq-pll.c b/drivers/clk/qcom/apss-ipq-pll.c
index 678b805f13d45..11f1ae59438f7 100644
--- a/drivers/clk/qcom/apss-ipq-pll.c
+++ b/drivers/clk/qcom/apss-ipq-pll.c
@@ -55,6 +55,24 @@ static struct clk_alpha_pll ipq_pll_huayra = {
},
};

+static struct clk_alpha_pll ipq_pll_stromer = {
+ .offset = 0x0,
+ .regs = ipq_pll_offsets[CLK_ALPHA_PLL_TYPE_STROMER_PLUS],
+ .flags = SUPPORTS_DYNAMIC_UPDATE,
+ .clkr = {
+ .enable_reg = 0x0,
+ .enable_mask = BIT(0),
+ .hw.init = &(struct clk_init_data){
+ .name = "a53pll",
+ .parent_data = &(const struct clk_parent_data) {
+ .fw_name = "xo",
+ },
+ .num_parents = 1,
+ .ops = &clk_alpha_pll_stromer_ops,
+ },
+ },
+};
+
static struct clk_alpha_pll ipq_pll_stromer_plus = {
.offset = 0x0,
.regs = ipq_pll_offsets[CLK_ALPHA_PLL_TYPE_STROMER_PLUS],
@@ -145,7 +163,7 @@ struct apss_pll_data {

static const struct apss_pll_data ipq5018_pll_data = {
.pll_type = CLK_ALPHA_PLL_TYPE_STROMER_PLUS,
- .pll = &ipq_pll_stromer_plus,
+ .pll = &ipq_pll_stromer,
.pll_config = &ipq5018_pll_config,
};


---
base-commit: e8f897f4afef0031fe618a8e94127a0934896aba
change-id: 20240311-apss-ipq-pll-ipq5018-hang-74d9a8f47136

Best regards,
--
Gabor Juhos <j4g8y7@xxxxxxxxx>