On 07/06/17 22:55, Heiner Kallweit wrote:
Am 07.06.2017 um 18:19 schrieb Srinivas Kandagatla:
On 04/06/17 12:06, Heiner Kallweit wrote:
Add a device-managed version of nvmem_register.
Signed-off-by: Heiner Kallweit <[email protected]>
---
Documentation/nvmem/nvmem.txt | 1 +
drivers/nvmem/core.c | 35 +++++++++++++++++++++++++++++++++++
include/linux/nvmem-provider.h | 7 +++++++
3 files changed, 43 insertions(+)
Thanks for the patch, one comments..
diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.txt
index dbd40d87..b4ff7862 100644
--- a/Documentation/nvmem/nvmem.txt
+++ b/Documentation/nvmem/nvmem.txt
@@ -37,6 +37,7 @@ and write the non-volatile memory.
A NVMEM provider can register with NVMEM core by supplying relevant
nvmem configuration to nvmem_register(), on success core would return a valid
nvmem_device pointer.
+devm_nvmem_register() is a device-managed version of nvmem_register.
nvmem_unregister(nvmem) is used to unregister a previously registered
provider.
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 783eb431..55db219f 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -531,6 +531,41 @@ int nvmem_unregister(struct nvmem_device *nvmem)
}
EXPORT_SYMBOL_GPL(nvmem_unregister);
+static void devm_nvmem_release(struct device *dev, void *res)
+{
+ nvmem_unregister(*(struct nvmem_device **)res);
nvmem_unregister() can fail, how are you going to deal with this error cases?
As stated in my answer to your other review comment:
Currently no caller of nvmem_unregister checks the return code.
Currently all nvmem provider drivers check return code of unregister in
remove path.
Checking the refcount I see more as a debug feature and I think making
No, I don't think its a debug feature!! without this check we would end
up dereferencing a freed pointer.
nvmem_unregister return void plus a WARN() if refcount != 0 would be better.
WARN() would not be enough to stop the system to crash, in case the
provider just unregisters with active users.
Rgds, Heiner
+}
+
+/**
+ * devm_nvmem_register() - managed version of nvmem_register
+ *
+ * @config: nvmem device configuration with which nvmem device is created.
+ *
+ * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
+ * on success.
+ */
+
+struct nvmem_device *devm_nvmem_register(const struct nvmem_config *config)
For consistency reasons, devm versions of apis should always have dev at as
first argument.
+{
+ struct nvmem_device *nv, **dr;
+
+ dr = devres_alloc(devm_nvmem_release, sizeof(*dr), GFP_KERNEL);
+ if (!dr)
+ return ERR_PTR(-ENOMEM);
+
+ nv = nvmem_register(config);
+ if (IS_ERR(nv)) {
+ devres_free(dr);
+ return nv;
+ }
+
+ *dr = nv;
+ devres_add(config->dev, dr);
+
+ return nv;
+}
+EXPORT_SYMBOL_GPL(devm_nvmem_register);
+
