ACPI: Use ACPI companion to match only the first physical device (52870786) · Commits · 戴 / test

drivers/acpi/scan.c

+54 −16

Original line number	Original line	Diff line number	Diff line
	@@ -141,6 +141,53 @@ static int create_modalias(struct acpi_device acpi_dev, char modalias,
	return len;		return len;
	}		}

			/*
			* acpi_companion_match() - Can we match via ACPI companion device
			* @dev: Device in question
			*
			* Check if the given device has an ACPI companion and if that companion has
			* a valid list of PNP IDs, and if the device is the first (primary) physical
			* device associated with it.
			*
			* If multiple physical devices are attached to a single ACPI companion, we need
			* to be careful. The usage scenario for this kind of relationship is that all
			* of the physical devices in question use resources provided by the ACPI
			* companion. A typical case is an MFD device where all the sub-devices share
			* the parent's ACPI companion. In such cases we can only allow the primary
			* (first) physical device to be matched with the help of the companion's PNP
			* IDs.
			*
			* Additional physical devices sharing the ACPI companion can still use
			* resources available from it but they will be matched normally using functions
			* provided by their bus types (and analogously for their modalias).
			*/
			static bool acpi_companion_match(const struct device *dev)
			{
			struct acpi_device *adev;
			bool ret;

			adev = ACPI_COMPANION(dev);
			if (!adev)
			return false;

			if (list_empty(&adev->pnp.ids))
			return false;

			mutex_lock(&adev->physical_node_lock);
			if (list_empty(&adev->physical_node_list)) {
			ret = false;
			} else {
			const struct acpi_device_physical_node *node;

			node = list_first_entry(&adev->physical_node_list,
			struct acpi_device_physical_node, node);
			ret = node->dev == dev;
			}
			mutex_unlock(&adev->physical_node_lock);

			return ret;
			}

	/*		/*
	* Creates uevent modalias field for ACPI enumerated devices.		* Creates uevent modalias field for ACPI enumerated devices.
	* Because the other buses does not support ACPI HIDs & CIDs.		* Because the other buses does not support ACPI HIDs & CIDs.
	@@ -149,20 +196,14 @@ static int create_modalias(struct acpi_device acpi_dev, char modalias,
	*/		*/
	int acpi_device_uevent_modalias(struct device dev, struct kobj_uevent_env env)		int acpi_device_uevent_modalias(struct device dev, struct kobj_uevent_env env)
	{		{
	struct acpi_device *acpi_dev;
	int len;		int len;

	acpi_dev = ACPI_COMPANION(dev);		if (!acpi_companion_match(dev))
	if (!acpi_dev)
	return -ENODEV;

	/* Fall back to bus specific way of modalias exporting */
	if (list_empty(&acpi_dev->pnp.ids))
	return -ENODEV;		return -ENODEV;

	if (add_uevent_var(env, "MODALIAS="))		if (add_uevent_var(env, "MODALIAS="))
	return -ENOMEM;		return -ENOMEM;
	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],		len = create_modalias(ACPI_COMPANION(dev), &env->buf[env->buflen - 1],
	sizeof(env->buf) - env->buflen);		sizeof(env->buf) - env->buflen);
	if (len <= 0)		if (len <= 0)
	return len;		return len;
	@@ -179,18 +220,12 @@ EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
	*/		*/
	int acpi_device_modalias(struct device dev, char buf, int size)		int acpi_device_modalias(struct device dev, char buf, int size)
	{		{
	struct acpi_device *acpi_dev;
	int len;		int len;

	acpi_dev = ACPI_COMPANION(dev);		if (!acpi_companion_match(dev))
	if (!acpi_dev)
	return -ENODEV;		return -ENODEV;

	/* Fall back to bus specific way of modalias exporting */		len = create_modalias(ACPI_COMPANION(dev), buf, size -1);
	if (list_empty(&acpi_dev->pnp.ids))
	return -ENODEV;

	len = create_modalias(acpi_dev, buf, size -1);
	if (len <= 0)		if (len <= 0)
	return len;		return len;
	buf[len++] = '\n';		buf[len++] = '\n';
	@@ -853,6 +888,9 @@ const struct acpi_device_id acpi_match_device(const struct acpi_device_id ids,
	if (!ids \|\| !handle \|\| acpi_bus_get_device(handle, &adev))		if (!ids \|\| !handle \|\| acpi_bus_get_device(handle, &adev))
	return NULL;		return NULL;

			if (!acpi_companion_match(dev))
			return NULL;

	return __acpi_match_device(adev, ids);		return __acpi_match_device(adev, ids);
	}		}
	EXPORT_SYMBOL_GPL(acpi_match_device);		EXPORT_SYMBOL_GPL(acpi_match_device);

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