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driver core: fw_devlink: Handle suppliers that don't use driver core

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Device links only work between devices that use the driver core to match
and bind a driver to a device. So, add an API for frameworks to let the
driver core know that a fwnode has been initialized by a driver without
using the driver core.

Then use this information to make sure that fw_devlink doesn't make the
consumers wait indefinitely on suppliers that'll never bind to a driver.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210205222644.2357303-6-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Saravana Kannan 2021-02-05 14:26:41 -08:00 committed by Greg Kroah-Hartman
parent a9dd8f3c2c
commit 74c782cff7
2 changed files with 32 additions and 2 deletions
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15
drivers/base/core.c
View File

@ -1636,6 +1636,17 @@ static int fw_devlink_create_devlink(struct device *con,
sup_dev = get_dev_from_fwnode(sup_handle);
if (sup_dev) {
/*
* If it's one of those drivers that don't actually bind to
* their device using driver core, then don't wait on this
* supplier device indefinitely.
*/
if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
ret = -EINVAL;
goto out;
}
/*
* If this fails, it is due to cycles in device links. Just
* give up on this link and treat it as invalid.
@ -1655,6 +1666,10 @@ static int fw_devlink_create_devlink(struct device *con,
goto out;
}
/* Supplier that's already initialized without a struct device. */
if (sup_handle->flags & FWNODE_FLAG_INITIALIZED)
return -EINVAL;
/*
* DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports
* cycles. So cycle detection isn't necessary and shouldn't be

19
include/linux/fwnode.h
View File

@ -11,6 +11,7 @@
#include <linux/types.h>
#include <linux/list.h>
#include <linux/err.h>
struct fwnode_operations;
struct device;
@ -18,11 +19,13 @@ struct device;
/*
* fwnode link flags
*
* LINKS_ADDED: The fwnode has already be parsed to add fwnode links.
* NOT_DEVICE: The fwnode will never be populated as a struct device.
* LINKS_ADDED: The fwnode has already be parsed to add fwnode links.
* NOT_DEVICE: The fwnode will never be populated as a struct device.
* INITIALIZED: The hardware corresponding to fwnode has been initialized.
*/
#define FWNODE_FLAG_LINKS_ADDED BIT(0)
#define FWNODE_FLAG_NOT_DEVICE BIT(1)
#define FWNODE_FLAG_INITIALIZED BIT(2)
struct fwnode_handle {
struct fwnode_handle *secondary;
@ -161,6 +164,18 @@ static inline void fwnode_init(struct fwnode_handle *fwnode,
INIT_LIST_HEAD(&fwnode->suppliers);
}
static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode,
bool initialized)
{
if (IS_ERR_OR_NULL(fwnode))
return;
if (initialized)
fwnode->flags |= FWNODE_FLAG_INITIALIZED;
else
fwnode->flags &= ~FWNODE_FLAG_INITIALIZED;
}
extern u32 fw_devlink_get_flags(void);
extern bool fw_devlink_is_strict(void);
int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);