Re: [PATCH v3 3/7] clk: Add of_clk_hw_register() API for early clk drivers
From: Jeffrey Hugo
Date: Mon Apr 08 2019 - 17:46:22 EST
On 4/4/2019 3:53 PM, Stephen Boyd wrote:
In some circumstances drivers register clks early and don't have access
to a struct device because the device model isn't initialized yet. Add
an API to let drivers register clks associated with a struct device_node
so that these drivers can participate in getting parent clks through DT.
NACK. This patch broke boot for me. I had to pull the below from JTAG.
What do you need to debug this?
[ 0.000000] Unable to handle kernel read from unreadable memory at
virtual address 0000000000000280
[ 0.000000] Mem abort info:
[ 0.000000] ESR = 0x96000004
[ 0.000000] Exception class = DABT (current EL), IL = 32 bits
[ 0.000000] SET = 0, FnV = 0
[ 0.000000] EA = 0, S1PTW = 0
[ 0.000000] Data abort info:
[ 0.000000] ISV = 0, ISS = 0x00000004
[ 0.000000] CM = 0, WnR = 0
[ 0.000000] [0000000000000280] user address but active_mm is swapper
[ 0.000000] Internal error: Oops: 96000004 [#1] SMP
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.1.0-rc1+ #453
[ 0.000000] Hardware name: Qualcomm Technologies, Inc. MSM8998 v1 MTP
(DT)
[ 0.000000] pstate: 60400085 (nZCv daIf +PAN -UAO)
[ 0.000000] pc : clk_hw_register+0x24/0x40
[ 0.000000] lr : clk_hw_register_fixed_rate_with_accuracy+0xac/0x100
[ 0.000000] sp : ffff0000117d3df0
[ 0.000000] x29: ffff0000117d3df0 x28: ffff8000fdc7cd28
[ 0.000000] x27: dead000000000100 x26: dead000000000200
[ 0.000000] x25: 0000000000000001 x24: ffff7dfffe80047c
[ 0.000000] x23: 000000000124f800 x22: 0000000000000000
[ 0.000000] x21: 0000000000000000 x20: ffff8000f9524c00
[ 0.000000] x19: 0000000000000000 x18: ffffffffffffffff
[ 0.000000] x17: 0000000000000000 x16: 0000000000000000
[ 0.000000] x15: ffff0000117dc708 x14: ffffffffffffffff
[ 0.000000] x13: 0000000000000020 x12: 0101010101010101
[ 0.000000] x11: 7f7f7f7f7f7f7f7f x10: 02fefeff01fefeff
[ 0.000000] x9 : 0000000000000000 x8 : ffff8000f9524c80
[ 0.000000] x7 : 0000000000000000 x6 : 000000000000003f
[ 0.000000] x5 : 0000000000000040 x4 : 0000000000000000
[ 0.000000] x3 : 0000000000000000 x2 : ffff8000f9524c00
[ 0.000000] x1 : ffff8000f9524c00 x0 : 0000000000000000
[ 0.000000] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____))
[ 0.000000] Call trace:
[ 0.000000] clk_hw_register+0x24/0x40
[ 0.000000] clk_hw_register_fixed_rate_with_accuracy+0xac/0x100
[ 0.000000] _of_fixed_clk_setup+0xa8/0x120
[ 0.000000] of_fixed_clk_setup+0x20/0x2c
[ 0.000000] of_clk_init+0x19c/0x254
[ 0.000000] time_init+0x18/0x4c
[ 0.000000] start_kernel+0x394/0x524
[ 0.000000] Code: aa1e03e0 d503201f aa1403e2 aa1303e0 (f9414261)
[ 0.000000] ---[ end trace 5d02af5e3cbab7bf ]---
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill
the idle task! ]---
Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Michael Turquette <mturquette@xxxxxxxxxxxx>
Cc: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
Cc: Chen-Yu Tsai <wens@xxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
---
drivers/clk/clk.c | 26 +++++++++++++++++++++++---
include/linux/clk-provider.h | 1 +
2 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index d27775a73e67..4971e9651ca5 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -45,6 +45,7 @@ struct clk_core {
struct clk_hw *hw;
struct module *owner;
struct device *dev;
+ struct device_node *of_node;
struct clk_core *parent;
const char **parent_names;
struct clk_core **parents;
@@ -3313,7 +3314,8 @@ struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
return clk;
}
-static struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
+static struct clk *
+__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
{
int i, ret;
struct clk_core *core;
@@ -3339,6 +3341,7 @@ static struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
if (dev && pm_runtime_enabled(dev))
core->rpm_enabled = true;
core->dev = dev;
+ core->of_node = np;
if (dev && dev->driver)
core->owner = dev->driver->owner;
core->hw = hw;
@@ -3429,7 +3432,7 @@ static struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
*/
struct clk *clk_register(struct device *dev, struct clk_hw *hw)
{
- return __clk_register(dev, hw);
+ return __clk_register(dev, dev->of_node, hw);
}
EXPORT_SYMBOL_GPL(clk_register);
@@ -3445,10 +3448,27 @@ EXPORT_SYMBOL_GPL(clk_register);
*/
int clk_hw_register(struct device *dev, struct clk_hw *hw)
{
- return PTR_ERR_OR_ZERO(__clk_register(dev, hw));
+ return PTR_ERR_OR_ZERO(__clk_register(dev, dev->of_node, hw));
}
EXPORT_SYMBOL_GPL(clk_hw_register);
+/*
+ * of_clk_hw_register - register a clk_hw and return an error code
+ * @node: device_node of device that is registering this clock
+ * @hw: link to hardware-specific clock data
+ *
+ * of_clk_hw_register() is the primary interface for populating the clock tree
+ * with new clock nodes when a struct device is not available, but a struct
+ * device_node is. It returns an integer equal to zero indicating success or
+ * less than zero indicating failure. Drivers must test for an error code after
+ * calling of_clk_hw_register().
+ */
+int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
+{
+ return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
+}
+EXPORT_SYMBOL_GPL(of_clk_hw_register);
+
/* Free memory allocated for a clock. */
static void __clk_release(struct kref *ref)
{
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index b7cf80a71293..7d2d97e15b76 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -773,6 +773,7 @@ struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw);
int __must_check clk_hw_register(struct device *dev, struct clk_hw *hw);
int __must_check devm_clk_hw_register(struct device *dev, struct clk_hw *hw);
+int __must_check of_clk_hw_register(struct device_node *node, struct clk_hw *hw);
void clk_unregister(struct clk *clk);
void devm_clk_unregister(struct device *dev, struct clk *clk);
--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.