[PATCH 0/2] clk: qcom: gcc-sm8550: Fix shared clk parking breakage

[PATCH 0/2] clk: qcom: gcc-sm8550: Fix shared clk parking breakage

[Stephen Boyd]

Amit Pundir reported[1] that a recent commit 01a0a6cc8cfd ("clk: qcom:
Park shared RCGs upon registration") broke USB and audio on sm8550-hdk.
These two patches fix the issue by skipping the parking bit of the
shared RCGs for devices that can't run so slow.

[1] https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com/

Stephen Boyd (2):
  clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs
  clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

 drivers/clk/qcom/clk-rcg.h    |  1 +
 drivers/clk/qcom/clk-rcg2.c   | 30 +++++++++++++++++++
 drivers/clk/qcom/gcc-sm8550.c | 54 +++++++++++++++++------------------
 3 files changed, 58 insertions(+), 27 deletions(-)


base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
-- 
https://chromeos.dev

[PATCH 1/2] clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs

[Stephen Boyd]

The QUPs aren't shared in a way that requires parking the RCG at an
always on parent in case some other entity turns on the clk. The
hardware is capable of setting a new frequency itself with the DFS mode,
so parking is unnecessary. Furthermore, there aren't any GDSCs for these
devices, so there isn't a possibility of the GDSC turning on the clks
for housekeeping purposes.

This wasn't a problem to mark these clks shared until we started parking
shared RCGs at clk registration time in commit 01a0a6cc8cfd ("clk: qcom:
Park shared RCGs upon registration"). Parking at init is actually
harmful to the UART when earlycon is used. If the device is pumping out
data while the frequency changes you'll see garbage on the serial
console until the driver can probe and actually set a proper frequency.

Revert the QUP part of commit 929c75d57566 ("clk: qcom: gcc-sm8550: Mark
RCGs shared where applicable") so that the QUPs don't get parked during
clk registration and break UART operations.

Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
Cc: Konrad Dybcio <konradybcio@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Taniya Das <quic_tdas@quicinc.com>
Reported-by: Amit Pundir <amit.pundir@linaro.org>
Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/clk/qcom/gcc-sm8550.c | 52 +++++++++++++++++------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/clk/qcom/gcc-sm8550.c b/drivers/clk/qcom/gcc-sm8550.c
index 7944ddb4b47d..0244a05866b8 100644
--- a/drivers/clk/qcom/gcc-sm8550.c
+++ b/drivers/clk/qcom/gcc-sm8550.c
@@ -536,7 +536,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s0_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -551,7 +551,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s1_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -566,7 +566,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s2_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -581,7 +581,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s3_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -596,7 +596,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s4_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -611,7 +611,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s5_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -626,7 +626,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s6_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -641,7 +641,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s7_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -656,7 +656,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s8_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -671,7 +671,7 @@ static struct clk_rcg2 gcc_qupv3_i2c_s9_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_ops,
 	},
 };
 
@@ -700,7 +700,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s0_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s0_clk_src = {
@@ -717,7 +717,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s1_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s1_clk_src = {
@@ -750,7 +750,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s2_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s2_clk_src = {
@@ -767,7 +767,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s3_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s3_clk_src = {
@@ -784,7 +784,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s4_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s4_clk_src = {
@@ -801,7 +801,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s5_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s5_clk_src = {
@@ -818,7 +818,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s6_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s6_clk_src = {
@@ -835,7 +835,7 @@ static struct clk_init_data gcc_qupv3_wrap1_s7_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap1_s7_clk_src = {
@@ -852,7 +852,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s0_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s0_clk_src = {
@@ -869,7 +869,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s1_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s1_clk_src = {
@@ -886,7 +886,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s2_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s2_clk_src = {
@@ -903,7 +903,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s3_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s3_clk_src = {
@@ -920,7 +920,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s4_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s4_clk_src = {
@@ -937,7 +937,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s5_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s5_clk_src = {
@@ -975,7 +975,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s6_clk_src_init = {
 	.parent_data = gcc_parent_data_8,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_8),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s6_clk_src = {
@@ -992,7 +992,7 @@ static struct clk_init_data gcc_qupv3_wrap2_s7_clk_src_init = {
 	.parent_data = gcc_parent_data_0,
 	.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 	.flags = CLK_SET_RATE_PARENT,
-	.ops = &clk_rcg2_shared_ops,
+	.ops = &clk_rcg2_ops,
 };
 
 static struct clk_rcg2 gcc_qupv3_wrap2_s7_clk_src = {
-- 
https://chromeos.dev

Re: [PATCH 1/2] clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs

[Stephen Boyd]

Quoting Stephen Boyd (2024-08-19 16:36:26)
> The QUPs aren't shared in a way that requires parking the RCG at an
> always on parent in case some other entity turns on the clk. The
> hardware is capable of setting a new frequency itself with the DFS mode,
> so parking is unnecessary. Furthermore, there aren't any GDSCs for these
> devices, so there isn't a possibility of the GDSC turning on the clks
> for housekeeping purposes.
>
> This wasn't a problem to mark these clks shared until we started parking
> shared RCGs at clk registration time in commit 01a0a6cc8cfd ("clk: qcom:
> Park shared RCGs upon registration"). Parking at init is actually
> harmful to the UART when earlycon is used. If the device is pumping out
> data while the frequency changes you'll see garbage on the serial
> console until the driver can probe and actually set a proper frequency.
>
> Revert the QUP part of commit 929c75d57566 ("clk: qcom: gcc-sm8550: Mark
> RCGs shared where applicable") so that the QUPs don't get parked during
> clk registration and break UART operations.
>
> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
> Cc: Konrad Dybcio <konradybcio@kernel.org>
> Cc: Bjorn Andersson <andersson@kernel.org>
> Cc: Taniya Das <quic_tdas@quicinc.com>
> Reported-by: Amit Pundir <amit.pundir@linaro.org>
> Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---

Applied to clk-fixes

[PATCH 2/2] clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

[Stephen Boyd]

Amit Pundir reports that audio and USB-C host mode stops working if the
gcc_usb30_prim_master_clk_src clk is registered and
clk_rcg2_shared_init() parks it on XO. Skip parking this clk at
registration time to fix those issues.

Partially revert commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
registration") by skipping the parking bit for this clk, but keep the
part where we cache the config register. That's still necessary to
figure out the true parent of the clk at registration time.

Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
Cc: Konrad Dybcio <konradybcio@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Taniya Das <quic_tdas@quicinc.com>
Reported-by: Amit Pundir <amit.pundir@linaro.org>
Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/clk/qcom/clk-rcg.h    |  1 +
 drivers/clk/qcom/clk-rcg2.c   | 30 ++++++++++++++++++++++++++++++
 drivers/clk/qcom/gcc-sm8550.c |  2 +-
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
index d7414361e432..8e0f3372dc7a 100644
--- a/drivers/clk/qcom/clk-rcg.h
+++ b/drivers/clk/qcom/clk-rcg.h
@@ -198,6 +198,7 @@ extern const struct clk_ops clk_byte2_ops;
 extern const struct clk_ops clk_pixel_ops;
 extern const struct clk_ops clk_gfx3d_ops;
 extern const struct clk_ops clk_rcg2_shared_ops;
+extern const struct clk_ops clk_rcg2_shared_no_init_park_ops;
 extern const struct clk_ops clk_dp_ops;
 
 struct clk_rcg_dfs_data {
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index 30b19bd39d08..bf26c5448f00 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -1348,6 +1348,36 @@ const struct clk_ops clk_rcg2_shared_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_rcg2_shared_ops);
 
+static int clk_rcg2_shared_no_init_park(struct clk_hw *hw)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+
+	/*
+	 * Read the config register so that the parent is properly mapped at
+	 * registration time.
+	 */
+	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &rcg->parked_cfg);
+
+	return 0;
+}
+
+/*
+ * Like clk_rcg2_shared_ops but skip the init so that the clk frequency is left
+ * unchanged at registration time.
+ */
+const struct clk_ops clk_rcg2_shared_no_init_park_ops = {
+	.init = clk_rcg2_shared_no_init_park,
+	.enable = clk_rcg2_shared_enable,
+	.disable = clk_rcg2_shared_disable,
+	.get_parent = clk_rcg2_shared_get_parent,
+	.set_parent = clk_rcg2_shared_set_parent,
+	.recalc_rate = clk_rcg2_shared_recalc_rate,
+	.determine_rate = clk_rcg2_determine_rate,
+	.set_rate = clk_rcg2_shared_set_rate,
+	.set_rate_and_parent = clk_rcg2_shared_set_rate_and_parent,
+};
+EXPORT_SYMBOL_GPL(clk_rcg2_shared_no_init_park_ops);
+
 /* Common APIs to be used for DFS based RCGR */
 static void clk_rcg2_dfs_populate_freq(struct clk_hw *hw, unsigned int l,
 				       struct freq_tbl *f)
diff --git a/drivers/clk/qcom/gcc-sm8550.c b/drivers/clk/qcom/gcc-sm8550.c
index 0244a05866b8..5abaeddd6afc 100644
--- a/drivers/clk/qcom/gcc-sm8550.c
+++ b/drivers/clk/qcom/gcc-sm8550.c
@@ -1159,7 +1159,7 @@ static struct clk_rcg2 gcc_usb30_prim_master_clk_src = {
 		.parent_data = gcc_parent_data_0,
 		.num_parents = ARRAY_SIZE(gcc_parent_data_0),
 		.flags = CLK_SET_RATE_PARENT,
-		.ops = &clk_rcg2_shared_ops,
+		.ops = &clk_rcg2_shared_no_init_park_ops,
 	},
 };
 
-- 
https://chromeos.dev

Re: [PATCH 2/2] clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

[Stephen Boyd]

Quoting Stephen Boyd (2024-08-19 16:36:27)
> Amit Pundir reports that audio and USB-C host mode stops working if the
> gcc_usb30_prim_master_clk_src clk is registered and
> clk_rcg2_shared_init() parks it on XO. Skip parking this clk at
> registration time to fix those issues.
>
> Partially revert commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
> registration") by skipping the parking bit for this clk, but keep the
> part where we cache the config register. That's still necessary to
> figure out the true parent of the clk at registration time.
>
> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
> Cc: Konrad Dybcio <konradybcio@kernel.org>
> Cc: Bjorn Andersson <andersson@kernel.org>
> Cc: Taniya Das <quic_tdas@quicinc.com>
> Reported-by: Amit Pundir <amit.pundir@linaro.org>
> Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---

Applied to clk-fixes

Re: [PATCH 2/2] clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

[Stephen Boyd]

Quoting Stephen Boyd (2024-08-19 16:36:27)
> Amit Pundir reports that audio and USB-C host mode stops working if the
> gcc_usb30_prim_master_clk_src clk is registered and
> clk_rcg2_shared_init() parks it on XO. Skip parking this clk at
> registration time to fix those issues.
>
> Partially revert commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
> registration") by skipping the parking bit for this clk, but keep the
> part where we cache the config register. That's still necessary to
> figure out the true parent of the clk at registration time.
>
> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
> Cc: Konrad Dybcio <konradybcio@kernel.org>
> Cc: Bjorn Andersson <andersson@kernel.org>
> Cc: Taniya Das <quic_tdas@quicinc.com>
> Reported-by: Amit Pundir <amit.pundir@linaro.org>
> Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>  drivers/clk/qcom/clk-rcg.h    |  1 +
>  drivers/clk/qcom/clk-rcg2.c   | 30 ++++++++++++++++++++++++++++++
>  drivers/clk/qcom/gcc-sm8550.c |  2 +-
>  3 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
> index d7414361e432..8e0f3372dc7a 100644
> --- a/drivers/clk/qcom/clk-rcg.h
> +++ b/drivers/clk/qcom/clk-rcg.h
> @@ -198,6 +198,7 @@ extern const struct clk_ops clk_byte2_ops;
>  extern const struct clk_ops clk_pixel_ops;
>  extern const struct clk_ops clk_gfx3d_ops;
>  extern const struct clk_ops clk_rcg2_shared_ops;
> +extern const struct clk_ops clk_rcg2_shared_no_init_park_ops;

I'm considering inverting these two rcg2_shared clk_ops so that only a
few clks are parked at clk registration time, to minimize the impact of
commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration").
We're up to three or four band-aids, that we can probably wait on
applying if we make all the shared RCGs determine the correct parent at
registration time but skip the parking, except for the display clks on
sc7180 where that exposes another problem with shared parents getting
turned off during probe. It's possible that other SoCs will want to park
their display clks as well to avoid that secondary problem, but it can
be an opt-in case instead of a change to all shared RCGs.

Re: [PATCH 2/2] clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

[Konrad Dybcio]

On 27.08.2024 8:12 PM, Stephen Boyd wrote:
> Quoting Stephen Boyd (2024-08-19 16:36:27)
>> Amit Pundir reports that audio and USB-C host mode stops working if the
>> gcc_usb30_prim_master_clk_src clk is registered and
>> clk_rcg2_shared_init() parks it on XO. Skip parking this clk at
>> registration time to fix those issues.
>>
>> Partially revert commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
>> registration") by skipping the parking bit for this clk, but keep the
>> part where we cache the config register. That's still necessary to
>> figure out the true parent of the clk at registration time.
>>
>> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
>> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
>> Cc: Konrad Dybcio <konradybcio@kernel.org>
>> Cc: Bjorn Andersson <andersson@kernel.org>
>> Cc: Taniya Das <quic_tdas@quicinc.com>
>> Reported-by: Amit Pundir <amit.pundir@linaro.org>
>> Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
>> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
>> ---
>>  drivers/clk/qcom/clk-rcg.h    |  1 +
>>  drivers/clk/qcom/clk-rcg2.c   | 30 ++++++++++++++++++++++++++++++
>>  drivers/clk/qcom/gcc-sm8550.c |  2 +-
>>  3 files changed, 32 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
>> index d7414361e432..8e0f3372dc7a 100644
>> --- a/drivers/clk/qcom/clk-rcg.h
>> +++ b/drivers/clk/qcom/clk-rcg.h
>> @@ -198,6 +198,7 @@ extern const struct clk_ops clk_byte2_ops;
>>  extern const struct clk_ops clk_pixel_ops;
>>  extern const struct clk_ops clk_gfx3d_ops;
>>  extern const struct clk_ops clk_rcg2_shared_ops;
>> +extern const struct clk_ops clk_rcg2_shared_no_init_park_ops;
> 
> I'm considering inverting these two rcg2_shared clk_ops so that only a
> few clks are parked at clk registration time, to minimize the impact of
> commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration").
> We're up to three or four band-aids, that we can probably wait on
> applying if we make all the shared RCGs determine the correct parent at
> registration time but skip the parking, except for the display clks on
> sc7180 where that exposes another problem with shared parents getting
> turned off during probe. It's possible that other SoCs will want to park
> their display clks as well to avoid that secondary problem, but it can
> be an opt-in case instead of a change to all shared RCGs.

Are all cases that need the parking obvious like it was the case on 7180,
i.e. some downstream branch is stuck and there's complaining in dmesg?

Konrad

Re: [PATCH 2/2] clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

[Stephen Boyd]

Quoting Konrad Dybcio (2024-08-30 05:24:20)
> On 27.08.2024 8:12 PM, Stephen Boyd wrote:
> > Quoting Stephen Boyd (2024-08-19 16:36:27)
> >> Amit Pundir reports that audio and USB-C host mode stops working if the
> >> gcc_usb30_prim_master_clk_src clk is registered and
> >> clk_rcg2_shared_init() parks it on XO. Skip parking this clk at
> >> registration time to fix those issues.
> >>
> >> Partially revert commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
> >> registration") by skipping the parking bit for this clk, but keep the
> >> part where we cache the config register. That's still necessary to
> >> figure out the true parent of the clk at registration time.
> >>
> >> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
> >> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
> >> Cc: Konrad Dybcio <konradybcio@kernel.org>
> >> Cc: Bjorn Andersson <andersson@kernel.org>
> >> Cc: Taniya Das <quic_tdas@quicinc.com>
> >> Reported-by: Amit Pundir <amit.pundir@linaro.org>
> >> Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
> >> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> >> ---
> >>  drivers/clk/qcom/clk-rcg.h    |  1 +
> >>  drivers/clk/qcom/clk-rcg2.c   | 30 ++++++++++++++++++++++++++++++
> >>  drivers/clk/qcom/gcc-sm8550.c |  2 +-
> >>  3 files changed, 32 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
> >> index d7414361e432..8e0f3372dc7a 100644
> >> --- a/drivers/clk/qcom/clk-rcg.h
> >> +++ b/drivers/clk/qcom/clk-rcg.h
> >> @@ -198,6 +198,7 @@ extern const struct clk_ops clk_byte2_ops;
> >>  extern const struct clk_ops clk_pixel_ops;
> >>  extern const struct clk_ops clk_gfx3d_ops;
> >>  extern const struct clk_ops clk_rcg2_shared_ops;
> >> +extern const struct clk_ops clk_rcg2_shared_no_init_park_ops;
> >
> > I'm considering inverting these two rcg2_shared clk_ops so that only a
> > few clks are parked at clk registration time, to minimize the impact of
> > commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration").
> > We're up to three or four band-aids, that we can probably wait on
> > applying if we make all the shared RCGs determine the correct parent at
> > registration time but skip the parking, except for the display clks on
> > sc7180 where that exposes another problem with shared parents getting
> > turned off during probe. It's possible that other SoCs will want to park
> > their display clks as well to avoid that secondary problem, but it can
> > be an opt-in case instead of a change to all shared RCGs.
>
> Are all cases that need the parking obvious like it was the case on 7180,
> i.e. some downstream branch is stuck and there's complaining in dmesg?
>

I'm under the impression that we need to park the clk when it is shared
by a remoteproc/firmware or is associated with a GDSC. It seems that on
older generations of hardware the GDSC would get unstuck eventually, but
newer generations stay broken and cause all sorts of havoc.

Note that in my statement earlier in this thread I'm talking about
parking the clk at registration time. That's done to avoid a problem
where a shared RCG turns off their parent PLL and another shared RCG is
also using that PLL but hasn't parked yet. The solution was to park at
registration time to fix that. It's mostly a workaround for the fact
that the clk framework doesn't have a good way to track dependencies for
all the child clks that are enable at registration time which want to
keep the parent PLL enabled. The problem is that it breaks things like
USB that has strict frequency requirements for the link.

Re: [PATCH 2/2] clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time

[Konrad Dybcio]

On 30.08.2024 7:59 PM, Stephen Boyd wrote:
> Quoting Konrad Dybcio (2024-08-30 05:24:20)
>> On 27.08.2024 8:12 PM, Stephen Boyd wrote:
>>> Quoting Stephen Boyd (2024-08-19 16:36:27)
>>>> Amit Pundir reports that audio and USB-C host mode stops working if the
>>>> gcc_usb30_prim_master_clk_src clk is registered and
>>>> clk_rcg2_shared_init() parks it on XO. Skip parking this clk at
>>>> registration time to fix those issues.
>>>>
>>>> Partially revert commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
>>>> registration") by skipping the parking bit for this clk, but keep the
>>>> part where we cache the config register. That's still necessary to
>>>> figure out the true parent of the clk at registration time.
>>>>
>>>> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
>>>> Fixes: 929c75d57566 ("clk: qcom: gcc-sm8550: Mark RCGs shared where applicable")
>>>> Cc: Konrad Dybcio <konradybcio@kernel.org>
>>>> Cc: Bjorn Andersson <andersson@kernel.org>
>>>> Cc: Taniya Das <quic_tdas@quicinc.com>
>>>> Reported-by: Amit Pundir <amit.pundir@linaro.org>
>>>> Closes: https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com
>>>> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
>>>> ---
>>>>  drivers/clk/qcom/clk-rcg.h    |  1 +
>>>>  drivers/clk/qcom/clk-rcg2.c   | 30 ++++++++++++++++++++++++++++++
>>>>  drivers/clk/qcom/gcc-sm8550.c |  2 +-
>>>>  3 files changed, 32 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
>>>> index d7414361e432..8e0f3372dc7a 100644
>>>> --- a/drivers/clk/qcom/clk-rcg.h
>>>> +++ b/drivers/clk/qcom/clk-rcg.h
>>>> @@ -198,6 +198,7 @@ extern const struct clk_ops clk_byte2_ops;
>>>>  extern const struct clk_ops clk_pixel_ops;
>>>>  extern const struct clk_ops clk_gfx3d_ops;
>>>>  extern const struct clk_ops clk_rcg2_shared_ops;
>>>> +extern const struct clk_ops clk_rcg2_shared_no_init_park_ops;
>>>
>>> I'm considering inverting these two rcg2_shared clk_ops so that only a
>>> few clks are parked at clk registration time, to minimize the impact of
>>> commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration").
>>> We're up to three or four band-aids, that we can probably wait on
>>> applying if we make all the shared RCGs determine the correct parent at
>>> registration time but skip the parking, except for the display clks on
>>> sc7180 where that exposes another problem with shared parents getting
>>> turned off during probe. It's possible that other SoCs will want to park
>>> their display clks as well to avoid that secondary problem, but it can
>>> be an opt-in case instead of a change to all shared RCGs.
>>
>> Are all cases that need the parking obvious like it was the case on 7180,
>> i.e. some downstream branch is stuck and there's complaining in dmesg?
>>
> 
> I'm under the impression that we need to park the clk when it is shared
> by a remoteproc/firmware or is associated with a GDSC. It seems that on
> older generations of hardware the GDSC would get unstuck eventually, but
> newer generations stay broken and cause all sorts of havoc.

I heard newer GDSCs are funky..

> Note that in my statement earlier in this thread I'm talking about
> parking the clk at registration time. That's done to avoid a problem
> where a shared RCG turns off their parent PLL and another shared RCG is
> also using that PLL but hasn't parked yet. The solution was to park at
> registration time to fix that. It's mostly a workaround for the fact
> that the clk framework doesn't have a good way to track dependencies for
> all the child clks that are enable at registration time which want to
> keep the parent PLL enabled. The problem is that it breaks things like
> USB that has strict frequency requirements for the link.

Should we just do something like .sync_state, where top-level parents
aren't turned off until all clocks have been registered?

Konrad

Re: [PATCH 0/2] clk: qcom: gcc-sm8550: Fix shared clk parking breakage

[Amit Pundir]

On Tue, 20 Aug 2024 at 05:06, Stephen Boyd <swboyd@chromium.org> wrote:
>
> Amit Pundir reported[1] that a recent commit 01a0a6cc8cfd ("clk: qcom:
> Park shared RCGs upon registration") broke USB and audio on sm8550-hdk.
> These two patches fix the issue by skipping the parking bit of the
> shared RCGs for devices that can't run so slow.
>
> [1] https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com/
>

Thank you for the patches Stephen. This series fixes the serial
console garbage, audio, and USB-C host mode regression I see on
SM8550-HDK running AOSP.

Tested-by: Amit Pundir <amit.pundir@linaro.org>


> Stephen Boyd (2):
>   clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs
>   clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time
>
>  drivers/clk/qcom/clk-rcg.h    |  1 +
>  drivers/clk/qcom/clk-rcg2.c   | 30 +++++++++++++++++++
>  drivers/clk/qcom/gcc-sm8550.c | 54 +++++++++++++++++------------------
>  3 files changed, 58 insertions(+), 27 deletions(-)
>
>
> base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
> --
> https://chromeos.dev
>

Re: [PATCH 0/2] clk: qcom: gcc-sm8550: Fix shared clk parking breakage

[neil.armstrong]

Hi,

On 20/08/2024 01:36, Stephen Boyd wrote:
> Amit Pundir reported[1] that a recent commit 01a0a6cc8cfd ("clk: qcom:
> Park shared RCGs upon registration") broke USB and audio on sm8550-hdk.
> These two patches fix the issue by skipping the parking bit of the
> shared RCGs for devices that can't run so slow.
> 
> [1] https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com/
> 
> Stephen Boyd (2):
>    clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs
>    clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time
> 
>   drivers/clk/qcom/clk-rcg.h    |  1 +
>   drivers/clk/qcom/clk-rcg2.c   | 30 +++++++++++++++++++
>   drivers/clk/qcom/gcc-sm8550.c | 54 +++++++++++++++++------------------
>   3 files changed, 58 insertions(+), 27 deletions(-)
> 
> 
> base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b

I'm pretty sure sm8450 & sm8650 (and probably other SoCs) could be also affected, could you check ?

Neil

Re: [PATCH 0/2] clk: qcom: gcc-sm8550: Fix shared clk parking breakage

[Stephen Boyd]

Quoting neil.armstrong@linaro.org (2024-08-21 08:44:00)
> Hi,
>
> On 20/08/2024 01:36, Stephen Boyd wrote:
> > Amit Pundir reported[1] that a recent commit 01a0a6cc8cfd ("clk: qcom:
> > Park shared RCGs upon registration") broke USB and audio on sm8550-hdk.
> > These two patches fix the issue by skipping the parking bit of the
> > shared RCGs for devices that can't run so slow.
> >
> > [1] https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com/
> >
> > Stephen Boyd (2):
> >    clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs
> >    clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time
> >
> >   drivers/clk/qcom/clk-rcg.h    |  1 +
> >   drivers/clk/qcom/clk-rcg2.c   | 30 +++++++++++++++++++
> >   drivers/clk/qcom/gcc-sm8550.c | 54 +++++++++++++++++------------------
> >   3 files changed, 58 insertions(+), 27 deletions(-)
> >
> >
> > base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
>
> I'm pretty sure sm8450 & sm8650 (and probably other SoCs) could be also affected, could you check ?

Does someone have the hardware to test? It looks like sm8450 isn't using
the shared ops, but sm8650 is, likely incorrectly.

Re: [PATCH 0/2] clk: qcom: gcc-sm8550: Fix shared clk parking breakage

[neil.armstrong]

On 23/08/2024 22:33, Stephen Boyd wrote:
> Quoting neil.armstrong@linaro.org (2024-08-21 08:44:00)
>> Hi,
>>
>> On 20/08/2024 01:36, Stephen Boyd wrote:
>>> Amit Pundir reported[1] that a recent commit 01a0a6cc8cfd ("clk: qcom:
>>> Park shared RCGs upon registration") broke USB and audio on sm8550-hdk.
>>> These two patches fix the issue by skipping the parking bit of the
>>> shared RCGs for devices that can't run so slow.
>>>
>>> [1] https://lore.kernel.org/CAMi1Hd1KQBE4kKUdAn8E5FV+BiKzuv+8FoyWQrrTHPDoYTuhgA@mail.gmail.com/
>>>
>>> Stephen Boyd (2):
>>>     clk: qcom: gcc-sm8550: Don't use parking clk_ops for QUPs
>>>     clk: qcom: gcc-sm8550: Don't park the USB RCG at registration time
>>>
>>>    drivers/clk/qcom/clk-rcg.h    |  1 +
>>>    drivers/clk/qcom/clk-rcg2.c   | 30 +++++++++++++++++++
>>>    drivers/clk/qcom/gcc-sm8550.c | 54 +++++++++++++++++------------------
>>>    3 files changed, 58 insertions(+), 27 deletions(-)
>>>
>>>
>>> base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
>>
>> I'm pretty sure sm8450 & sm8650 (and probably other SoCs) could be also affected, could you check ?
> 
> Does someone have the hardware to test? It looks like sm8450 isn't using
> the shared ops, but sm8650 is, likely incorrectly.

I can't reproduce the uart issue on 8650, I'll try moving some dependencies (CLK, ICC, ..) as modules.

Bryan reproduced it on X1, and he posted a patch.

Neil