Currently, of_nvmem_layout_get_container() returns NULL on error, or an
error pointer if either CONFIG_NVMEM or CONFIG_OF is turned off. We
should likely avoid this kind of mix for two reasons: to clarify the
intend and anyway fix the !CONFIG_OF which will likely always if we use
this helper somewhere else. Let's just return NULL when no layout is
found, we don't need an error value here.

Link: https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
Fixes: 266570f496b9 ("nvmem: core: introduce NVMEM layouts")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@intel.com/
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

---

Backports to stable kernels is likely not needed as I believe the error
pointer will be discarded "magically" by the of/ code.
---
 include/linux/nvmem-consumer.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index fa030d93b768..27373024856d 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -256,7 +256,7 @@ static inline struct nvmem_device *of_nvmem_device_get(struct device_node *np,
 static inline struct device_node *
 of_nvmem_layout_get_container(struct nvmem_device *nvmem)
 {
-	return ERR_PTR(-EOPNOTSUPP);
+	return NULL;
 }
 #endif /* CONFIG_NVMEM && CONFIG_OF */
 
-- 
2.34.1

Am 2023-08-08 08:29, schrieb Miquel Raynal:
> Currently, of_nvmem_layout_get_container() returns NULL on error, or an
> error pointer if either CONFIG_NVMEM or CONFIG_OF is turned off. We
> should likely avoid this kind of mix for two reasons: to clarify the
> intend and anyway fix the !CONFIG_OF which will likely always if we use
> this helper somewhere else. Let's just return NULL when no layout is
> found, we don't need an error value here.
> 
> Link: 
> https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
> Fixes: 266570f496b9 ("nvmem: core: introduce NVMEM layouts")
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@intel.com/
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Reviewed-by: Michael Walle <michael@walle.cc>