Commit 6847b00c authored by Gerhard Engleder's avatar Gerhard Engleder Committed by Greg Kroah-Hartman
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misc: keba: Fix kernfs warning on module unload 



Unloading the cp500 module leads to the following warning:

kernfs: can not remove 'eeprom', no directory
WARNING: CPU: 1 PID: 1610 at fs/kernfs/dir.c:1683 kernfs_remove_by_name_ns+0xb1/0xc0

The parent I2C device of the nvmem devices is freed before the nvmem
devices. The reference to the nvmem devices is put by devm after
cp500_remove(), but at this time the parent I2C device does not exist
anymore as the I2C controller and its devices have already been freed in
cp500_remove(). Thus, nvmem tries to remove an entry from an already
deleted directory.

Free nvmem devices before I2C controller auxiliary device.

Signed-off-by: default avatarGerhard Engleder <eg@keba.com>
Link: https://lore.kernel.org/r/20241214215759.60811-1-gerhard@engleder-embedded.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2d390e06

drivers/misc/keba/cp500.c

+45 −24
Original line number Diff line number Diff line
@@ -126,8 +126,9 @@ static struct cp500_devs cp520_devices = { 
};



struct cp500_nvmem {

	struct nvmem_device *nvmem;

	struct nvmem_device *base_nvmem;

	unsigned int offset;

	struct nvmem_device *nvmem;

};



struct cp500 {
@@ -581,8 +582,8 @@ static int cp500_nvmem_read(void *priv, unsigned int offset, void *val, 
	struct cp500_nvmem *nvmem = priv;

	int ret;



	ret = nvmem_device_read(nvmem->nvmem, nvmem->offset + offset, bytes,

				val);

	ret = nvmem_device_read(nvmem->base_nvmem, nvmem->offset + offset,

				bytes, val);

	if (ret != bytes)

		return ret;
@@ -595,15 +596,16 @@ static int cp500_nvmem_write(void *priv, unsigned int offset, void *val, 
	struct cp500_nvmem *nvmem = priv;

	int ret;



	ret = nvmem_device_write(nvmem->nvmem, nvmem->offset + offset, bytes,

				 val);

	ret = nvmem_device_write(nvmem->base_nvmem, nvmem->offset + offset,

				 bytes, val);

	if (ret != bytes)

		return ret;



	return 0;

}



static int cp500_nvmem_register(struct cp500 *cp500, struct nvmem_device *nvmem)

static int cp500_nvmem_register(struct cp500 *cp500,

				struct nvmem_device *base_nvmem)

{

	struct device *dev = &cp500->pci_dev->dev;

	struct nvmem_config nvmem_config = {};
@@ -625,27 +627,52 @@ static int cp500_nvmem_register(struct cp500 *cp500, struct nvmem_device *nvmem) 
	nvmem_config.reg_read = cp500_nvmem_read;

	nvmem_config.reg_write = cp500_nvmem_write;



	cp500->nvmem_cpu.nvmem = nvmem;

	cp500->nvmem_cpu.base_nvmem = base_nvmem;

	cp500->nvmem_cpu.offset = CP500_EEPROM_CPU_OFFSET;

	nvmem_config.name = CP500_EEPROM_CPU_NAME;

	nvmem_config.size = CP500_EEPROM_CPU_SIZE;

	nvmem_config.priv = &cp500->nvmem_cpu;

	tmp = devm_nvmem_register(dev, &nvmem_config);

	tmp = nvmem_register(&nvmem_config);

	if (IS_ERR(tmp))

		return PTR_ERR(tmp);

	cp500->nvmem_cpu.nvmem = tmp;



	cp500->nvmem_user.nvmem = nvmem;

	cp500->nvmem_user.base_nvmem = base_nvmem;

	cp500->nvmem_user.offset = CP500_EEPROM_USER_OFFSET;

	nvmem_config.name = CP500_EEPROM_USER_NAME;

	nvmem_config.size = CP500_EEPROM_USER_SIZE;

	nvmem_config.priv = &cp500->nvmem_user;

	tmp = devm_nvmem_register(dev, &nvmem_config);

	if (IS_ERR(tmp))

	tmp = nvmem_register(&nvmem_config);

	if (IS_ERR(tmp)) {

		nvmem_unregister(cp500->nvmem_cpu.nvmem);

		cp500->nvmem_cpu.nvmem = NULL;



		return PTR_ERR(tmp);

	}

	cp500->nvmem_user.nvmem = tmp;



	return 0;

}



static void cp500_nvmem_unregister(struct cp500 *cp500)

{

	int notified;



	if (cp500->nvmem_user.nvmem) {

		nvmem_unregister(cp500->nvmem_user.nvmem);

		cp500->nvmem_user.nvmem = NULL;

	}

	if (cp500->nvmem_cpu.nvmem) {

		nvmem_unregister(cp500->nvmem_cpu.nvmem);

		cp500->nvmem_cpu.nvmem = NULL;

	}



	/* CPU and user nvmem use the same base_nvmem, put only once */

	notified = atomic_read(&cp500->nvmem_notified);

	if (notified)

		nvmem_device_put(cp500->nvmem_cpu.base_nvmem);

}



static int cp500_nvmem_match(struct device *dev, const void *data)

{

	const struct cp500 *cp500 = data;
@@ -663,13 +690,6 @@ static int cp500_nvmem_match(struct device *dev, const void *data) 
	return 0;

}



static void cp500_devm_nvmem_put(void *data)

{

	struct nvmem_device *nvmem = data;



	nvmem_device_put(nvmem);

}



static int cp500_nvmem(struct notifier_block *nb, unsigned long action,

		       void *data)

{
@@ -698,10 +718,6 @@ static int cp500_nvmem(struct notifier_block *nb, unsigned long action, 
		return NOTIFY_DONE;

	}



	ret = devm_add_action_or_reset(dev, cp500_devm_nvmem_put, nvmem);

	if (ret)

		return ret;



	ret = cp500_nvmem_register(cp500, nvmem);

	if (ret)

		return ret;
@@ -932,12 +948,17 @@ static void cp500_remove(struct pci_dev *pci_dev) 
{

	struct cp500 *cp500 = pci_get_drvdata(pci_dev);



	/*

	 * unregister CPU and user nvmem and put base_nvmem before parent

	 * auxiliary device of base_nvmem is unregistered

	 */

	nvmem_unregister_notifier(&cp500->nvmem_notifier);

	cp500_nvmem_unregister(cp500);



	cp500_unregister_auxiliary_devs(cp500);



	cp500_disable(cp500);



	nvmem_unregister_notifier(&cp500->nvmem_notifier);



	pci_set_drvdata(pci_dev, 0);



	pci_free_irq_vectors(pci_dev);