Messages in this thread | | | Subject | Re: [PATCH v1 2/3] driver core: Update device link status properly for device_bind_driver() | From | Jon Hunter <> | Date | Fri, 12 Mar 2021 16:59:45 +0000 |
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On 02/03/2021 21:11, Saravana Kannan wrote: > Device link status was not getting updated correctly when > device_bind_driver() is called on a device. This causes a warning[1]. > Fix this by updating device links that can be updated and dropping > device links that can't be updated to a sensible state. > > [1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/ > Signed-off-by: Saravana Kannan <saravanak@google.com> > --- > drivers/base/base.h | 1 + > drivers/base/core.c | 35 +++++++++++++++++++++++++++++++++++ > drivers/base/dd.c | 4 +++- > 3 files changed, 39 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/base.h b/drivers/base/base.h > index 52b3d7b75c27..1b44ed588f66 100644 > --- a/drivers/base/base.h > +++ b/drivers/base/base.h > @@ -185,6 +185,7 @@ extern int device_links_read_lock(void); > extern void device_links_read_unlock(int idx); > extern int device_links_read_lock_held(void); > extern int device_links_check_suppliers(struct device *dev); > +extern void device_links_force_bind(struct device *dev); > extern void device_links_driver_bound(struct device *dev); > extern void device_links_driver_cleanup(struct device *dev); > extern void device_links_no_driver(struct device *dev); > diff --git a/drivers/base/core.c b/drivers/base/core.c > index f29839382f81..45c75cc96fdc 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -1153,6 +1153,41 @@ static ssize_t waiting_for_supplier_show(struct device *dev, > } > static DEVICE_ATTR_RO(waiting_for_supplier); > > +/** > + * device_links_force_bind - Prepares device to be force bound > + * @dev: Consumer device. > + * > + * device_bind_driver() force binds a device to a driver without calling any > + * driver probe functions. So the consumer really isn't going to wait for any > + * supplier before it's bound to the driver. We still want the device link > + * states to be sensible when this happens. > + * > + * In preparation for device_bind_driver(), this function goes through each > + * supplier device links and checks if the supplier is bound. If it is, then > + * the device link status is set to CONSUMER_PROBE. Otherwise, the device link > + * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored. > + */ > +void device_links_force_bind(struct device *dev) > +{ > + struct device_link *link, *ln; > + > + device_links_write_lock(); > + > + list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { > + if (!(link->flags & DL_FLAG_MANAGED)) > + continue; > + > + if (link->status != DL_STATE_AVAILABLE) { > + device_link_drop_managed(link); > + continue; > + } > + WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE); > + } > + dev->links.status = DL_DEV_PROBING; > + > + device_links_write_unlock(); > +} > + > /** > * device_links_driver_bound - Update device links after probing its driver. > * @dev: Device to update the links for. > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index f18963f42e21..eb201c6d5a6a 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -460,8 +460,10 @@ int device_bind_driver(struct device *dev) > int ret; > > ret = driver_sysfs_add(dev); > - if (!ret) > + if (!ret) { > + device_links_force_bind(dev); > driver_bound(dev); > + } > else if (dev->bus) > blocking_notifier_call_chain(&dev->bus->p->bus_notifier, > BUS_NOTIFY_DRIVER_NOT_BOUND, dev); >
Thanks, this fixes the problem I had observed.
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Cheers! Jon
-- nvpublic
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