diff mbox series

clk: qcom: gcc-sc8280xp: don't use parking clk_ops for QUPs

Message ID 20240902070830.8535-1-johan+linaro@kernel.org (mailing list archive)
State Accepted
Headers show
Series clk: qcom: gcc-sc8280xp: don't use parking clk_ops for QUPs | expand

Commit Message

Johan Hovold Sept. 2, 2024, 7:08 a.m. UTC 
A recent change started parking the RCG at an always on parent during
registration, something which specifically breaks handover from an early
serial console.

Quoting Stephen Boyd who fixed this issue for SM8550 [1]:

	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.

Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
Fixes: d65d005f9a6c ("clk: qcom: add sc8280xp GCC driver")
Link: https://lore.kernel.org/all/20240819233628.2074654-2-swboyd@chromium.org/ [1]
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/clk/qcom/gcc-sc8280xp.c | 48 ++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 24 deletions(-)

Comments

Stephen Boyd Sept. 3, 2024, 8:02 p.m. UTC | #1 
Quoting Johan Hovold (2024-09-02 00:08:30)
> A recent change started parking the RCG at an always on parent during
> registration, something which specifically breaks handover from an early
> serial console.
> 
> Quoting Stephen Boyd who fixed this issue for SM8550 [1]:
> 
>         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.
> 
> Fixes: 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon registration")
> Fixes: d65d005f9a6c ("clk: qcom: add sc8280xp GCC driver")
> Link: https://lore.kernel.org/all/20240819233628.2074654-2-swboyd@chromium.org/ [1]
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---

Applied to clk-fixes
diff mbox series

Patch

diff --git a/drivers/clk/qcom/gcc-sc8280xp.c b/drivers/clk/qcom/gcc-sc8280xp.c
index 5f11760cf73f..f27d0003f427 100644
--- a/drivers/clk/qcom/gcc-sc8280xp.c
+++ b/drivers/clk/qcom/gcc-sc8280xp.c
@@ -1500,7 +1500,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s0_clk_src = {
@@ -1517,7 +1517,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s1_clk_src = {
@@ -1534,7 +1534,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s2_clk_src = {
@@ -1551,7 +1551,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s3_clk_src = {
@@ -1568,7 +1568,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s4_clk_src = {
@@ -1585,7 +1585,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s5_clk_src = {
@@ -1617,7 +1617,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s6_clk_src = {
@@ -1634,7 +1634,7 @@  static struct clk_init_data gcc_qupv3_wrap0_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_wrap0_s7_clk_src = {
@@ -1651,7 +1651,7 @@  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 = {
@@ -1668,7 +1668,7 @@  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 = {
@@ -1685,7 +1685,7 @@  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 = {
@@ -1702,7 +1702,7 @@  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 = {
@@ -1719,7 +1719,7 @@  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 = {
@@ -1736,7 +1736,7 @@  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 = {
@@ -1753,7 +1753,7 @@  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 = {
@@ -1770,7 +1770,7 @@  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 = {
@@ -1787,7 +1787,7 @@  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 = {
@@ -1804,7 +1804,7 @@  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 = {
@@ -1821,7 +1821,7 @@  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 = {
@@ -1838,7 +1838,7 @@  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 = {
@@ -1855,7 +1855,7 @@  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 = {
@@ -1872,7 +1872,7 @@  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 = {
@@ -1889,7 +1889,7 @@  static struct clk_init_data gcc_qupv3_wrap2_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_wrap2_s6_clk_src = {
@@ -1906,7 +1906,7 @@  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 = {