[PATCH 0/3] Pwrseq/serdev fixes

[PATCH 0/3] Pwrseq/serdev fixes

[Manivannan Sadhasivam]

Hi Bartosz,

This series fixes build issues reported by kernel test robot on the recently
merged M.2 Key E pwrseq series.

Patches 2 and 3 can be squashed with offending commits, while patch 1 should be
applied separately.

- Mani 

Manivannan Sadhasivam (3):
  serdev: Add missing stubs for serdev APIs when CONFIG_SERIAL_DEV_BUS
    is not selected
  serdev: Add CONFIG_SERIAL_DEV_BUS guard for
    of_find_serdev_controller_by_node() API
  power: sequencing: pcie-m2: Guard the helper functions making use of
    PCI bus notifier

 drivers/power/sequencing/pwrseq-pcie-m2.c |  9 +++++
 include/linux/serdev.h                    | 46 +++++++++++++++++------
 2 files changed, 43 insertions(+), 12 deletions(-)

-- 
2.51.0

[PATCH 1/3] serdev: Add missing stubs for serdev APIs when CONFIG_SERIAL_DEV_BUS is not selected

[Manivannan Sadhasivam]

Some of the serdev APIs are not guarded by CONFIG_SERIAL_DEV_BUS and also
missing the stubs when the symbol is not selected. This leads to the below
build errors:

   drivers/power/sequencing/pwrseq-pcie-m2.o: in function `pwrseq_pcie_m2_remove_serdev':
>> pwrseq-pcie-m2.c:(.text+0x260): undefined reference to `serdev_device_remove'
   powerpc64-linux-ld: drivers/power/sequencing/pwrseq-pcie-m2.o: in function `pwrseq_m2_pcie_notify':
>> powerpc64-linux-ld: pwrseq-pcie-m2.c:(.text+0x9c8): undefined reference to `serdev_device_alloc'
>> powerpc64-linux-ld: pwrseq-pcie-m2.c:(.text+0xc00): undefined reference to `serdev_device_add'

Fix these issues by adding the CONFIG_SERIAL_DEV_BUS guard to function
prototypes and stubs when the symbol is not selected.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202604011226.KGNn5974-lkp@intel.com/
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 include/linux/serdev.h | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 188c0ba62d50..0de261a26284 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -156,16 +156,6 @@ static inline void serdev_controller_put(struct serdev_controller *ctrl)
 		put_device(&ctrl->dev);
 }
 
-struct serdev_device *serdev_device_alloc(struct serdev_controller *);
-int serdev_device_add(struct serdev_device *);
-void serdev_device_remove(struct serdev_device *);
-
-struct serdev_controller *serdev_controller_alloc(struct device *host,
-						  struct device *parent,
-						  size_t size);
-int serdev_controller_add(struct serdev_controller *);
-void serdev_controller_remove(struct serdev_controller *);
-
 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
 {
 	struct serdev_device *serdev = ctrl->serdev;
@@ -204,6 +194,16 @@ void serdev_device_write_wakeup(struct serdev_device *);
 ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
 void serdev_device_write_flush(struct serdev_device *);
 
+struct serdev_device *serdev_device_alloc(struct serdev_controller *);
+int serdev_device_add(struct serdev_device *);
+void serdev_device_remove(struct serdev_device *);
+
+struct serdev_controller *serdev_controller_alloc(struct device *host,
+						  struct device *parent,
+						  size_t size);
+int serdev_controller_add(struct serdev_controller *);
+void serdev_controller_remove(struct serdev_controller *);
+
 /*
  * serdev device driver functions
  */
@@ -264,6 +264,28 @@ static inline ssize_t serdev_device_write(struct serdev_device *sdev,
 }
 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
 
+static inline struct serdev_device *serdev_device_alloc(struct serdev_controller *)
+{
+	return NULL;
+}
+static inline int serdev_device_add(struct serdev_device *)
+{
+	return -ENODEV;
+}
+static inline void serdev_device_remove(struct serdev_device *) {}
+
+static inline struct serdev_controller *serdev_controller_alloc(struct device *host,
+						  struct device *parent,
+						  size_t size)
+{
+	return NULL;
+}
+static inline int serdev_controller_add(struct serdev_controller *)
+{
+	return -ENODEV;
+}
+static inline void serdev_controller_remove(struct serdev_controller *) {}
+
 #define serdev_device_driver_register(x)
 #define serdev_device_driver_unregister(x)
 
-- 
2.51.0

[PATCH 2/3] serdev: Add CONFIG_SERIAL_DEV_BUS guard for of_find_serdev_controller_by_node() API

[Manivannan Sadhasivam]

Currently, this API is only guarded by CONFIG_OF. But the function
definition is guarded by CONFIG_SERIAL_DEV_BUS symbol in the .c file. This
causes below build error if CONFIG_SERIAL_DEV_BUS is not selected but only
CONFIG_OF:

pwrseq-pcie-m2.c:(.text+0x924): undefined reference to `of_find_serdev_controller_by_node'

Fix this issue by adding the CONFIG_SERIAL_DEV_BUS guard to the function
prototype.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202604011226.KGNn5974-lkp@intel.com/
Fixes: a2b4814190af ("serdev: Add an API to find the serdev controller associated with the devicetree node")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 include/linux/serdev.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 0de261a26284..58f000534bdb 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -356,13 +356,13 @@ static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 }
 #endif /* CONFIG_ACPI */
 
-#ifdef CONFIG_OF
+#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
 struct serdev_controller *of_find_serdev_controller_by_node(struct device_node *node);
 #else
 static inline struct serdev_controller *of_find_serdev_controller_by_node(struct device_node *node)
 {
 	return NULL;
 }
-#endif /* CONFIG_OF */
+#endif /* CONFIG_OF && CONFIG_SERIAL_DEV_BUS */
 
 #endif /*_LINUX_SERDEV_H */
-- 
2.51.0

[PATCH 3/3] power: sequencing: pcie-m2: Guard the helper functions making use of PCI bus notifier

[Manivannan Sadhasivam]

The PCI bus notifier is only visible if CONFIG_PCI symbol is selected in
Kconfig. But this driver can be built without CONFIG_PCI due to
CONFIG_COMPILE_TEST, leading to below build error:

   drivers/power/sequencing/pwrseq-pcie-m2.c: In function 'pwrseq_pcie_m2_free_resources':
>> drivers/power/sequencing/pwrseq-pcie-m2.c:185:34: error: 'pci_bus_type' undeclared (first use in this function); did you mean 'pci_pcie_type'?
     185 |         bus_unregister_notifier(&pci_bus_type, &ctx->nb);
         |                                  ^~~~~~~~~~~~
         |                                  pci_pcie_type
   drivers/power/sequencing/pwrseq-pcie-m2.c:185:34: note: each undeclared identifier is reported only once for each function it appears in
   drivers/power/sequencing/pwrseq-pcie-m2.c: In function 'pwrseq_pcie_m2_register_notifier':
   drivers/power/sequencing/pwrseq-pcie-m2.c:340:54: error: 'pci_bus_type' undeclared (first use in this function); did you mean 'pci_pcie_type'?
     340 |                         ret = bus_register_notifier(&pci_bus_type, &ctx->nb);
         |                                                      ^~~~~~~~~~~~
         |                                                      pci_pcie_type

So add guards to make sure that all these helper functions making use of
the PCI bus notifier are only compiled if CONFIG_PCI is selected.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202603180609.ucspJefN-lkp@intel.com
Fixes: 3f736aecbdc8 ("power: sequencing: pcie-m2: Create serdev device for WCN7850 bluetooth")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/power/sequencing/pwrseq-pcie-m2.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/power/sequencing/pwrseq-pcie-m2.c b/drivers/power/sequencing/pwrseq-pcie-m2.c
index a75ca4fda2eb..d3102fea8d93 100644
--- a/drivers/power/sequencing/pwrseq-pcie-m2.c
+++ b/drivers/power/sequencing/pwrseq-pcie-m2.c
@@ -177,6 +177,7 @@ static int pwrseq_pcie_m2_match(struct pwrseq_device *pwrseq,
 	return PWRSEQ_NO_MATCH;
 }
 
+#if IS_ENABLED(CONFIG_PCI)
 static int pwrseq_m2_pcie_create_bt_node(struct pwrseq_pcie_m2_ctx *ctx,
 					struct device_node *parent)
 {
@@ -374,6 +375,12 @@ static int pwrseq_pcie_m2_register_notifier(struct pwrseq_pcie_m2_ctx *ctx, stru
 
 	return 0;
 }
+#else
+static int pwrseq_pcie_m2_register_notifier(struct pwrseq_pcie_m2_ctx *ctx, struct device *dev)
+{
+	return 0;
+}
+#endif /* CONFIG_PCI */
 
 static int pwrseq_pcie_m2_probe(struct platform_device *pdev)
 {
@@ -452,8 +459,10 @@ static void pwrseq_pcie_m2_remove(struct platform_device *pdev)
 {
 	struct pwrseq_pcie_m2_ctx *ctx = platform_get_drvdata(pdev);
 
+#if IS_ENABLED(CONFIG_PCI)
 	bus_unregister_notifier(&pci_bus_type, &ctx->nb);
 	pwrseq_pcie_m2_remove_serdev(ctx);
+#endif
 
 	regulator_bulk_free(ctx->num_vregs, ctx->regs);
 }
-- 
2.51.0

Re: [PATCH 3/3] power: sequencing: pcie-m2: Guard the helper functions making use of PCI bus notifier

[kernel test robot]

Hi Manivannan,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linux-next/master]
[also build test WARNING on linus/master v6.16-rc1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Manivannan-Sadhasivam/serdev-Add-missing-stubs-for-serdev-APIs-when-CONFIG_SERIAL_DEV_BUS-is-not-selected/20260402-225703
base:   linux-next/master
patch link:    https://lore.kernel.org/r/20260401070735.107162-4-manivannan.sadhasivam%40oss.qualcomm.com
patch subject: [PATCH 3/3] power: sequencing: pcie-m2: Guard the helper functions making use of PCI bus notifier
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260403/202604030008.5exLAPFm-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260403/202604030008.5exLAPFm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604030008.5exLAPFm-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/tty/tty_port.c:20:
>> include/linux/serdev.h:268:83: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions]
     268 | static inline struct serdev_device *serdev_device_alloc(struct serdev_controller *)
         |                                                                                   ^
   include/linux/serdev.h:272:59: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions]
     272 | static inline int serdev_device_add(struct serdev_device *)
         |                                                           ^
   include/linux/serdev.h:276:63: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions]
     276 | static inline void serdev_device_remove(struct serdev_device *) {}
         |                                                               ^
   include/linux/serdev.h:284:67: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions]
     284 | static inline int serdev_controller_add(struct serdev_controller *)
         |                                                                   ^
   include/linux/serdev.h:288:71: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions]
     288 | static inline void serdev_controller_remove(struct serdev_controller *) {}
         |                                                                       ^
   5 warnings generated.


vim +268 include/linux/serdev.h

   267	
 > 268	static inline struct serdev_device *serdev_device_alloc(struct serdev_controller *)
   269	{
   270		return NULL;
   271	}
   272	static inline int serdev_device_add(struct serdev_device *)
   273	{
   274		return -ENODEV;
   275	}
   276	static inline void serdev_device_remove(struct serdev_device *) {}
   277	

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