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From: Gabor Juhos <j4g8y7@gmail.com>
Date: Mon, 11 Mar 2024 16:06:36 +0100
Subject: [PATCH] clk: qcom: apss-ipq-pll: use stromer ops for IPQ5018 to
 fix boot failure
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Message-Id: <20240311-apss-ipq-pll-ipq5018-hang-v1-1-8ed42b7a904d@gmail.com>
To: Bjorn Andersson <andersson@kernel.org>, 
 Konrad Dybcio <konrad.dybcio@linaro.org>, 
 Michael Turquette <mturquette@baylibre.com>, 
 Stephen Boyd <sboyd@kernel.org>, 
 Sricharan Ramabadhran <quic_srichara@quicinc.com>, 
 Dmitry Baryshkov <dmitry.baryshkov@linaro.org>, 
 Gokul Sriram Palanisamy <quic_gokulsri@quicinc.com>
Cc: linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org, 
 linux-kernel@vger.kernel.org, stable@vger.kernel.org, 
 Gabor Juhos <j4g8y7@gmail.com>

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@vger.kernel.org
Fixes: 50492f929486 ("clk: qcom: apss-ipq-pll: add support for IPQ5018")
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
---
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@gmail.com>