From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Saravana Kannan <saravanak@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Len Brown <lenb@kernel.org>,
kernel-team@android.com, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH v1 3/5] driver core: Allow fwnode_operations.add_links to differentiate errors
Date: Tue, 05 Nov 2019 23:43:08 +0100 [thread overview]
Message-ID: <7640808.4Pc6YCm0Y9@kreacher> (raw)
In-Reply-To: <20191028220027.251605-4-saravanak@google.com>
On Monday, October 28, 2019 11:00:24 PM CET Saravana Kannan wrote:
> When add_links() still has suppliers that it needs to link to in the
> future, this patch allows it to differentiate between suppliers that are
> needed for probing vs suppliers that are needed for sync_state()
> correctness.
I guess you mean that it will return different error codes in the different
cases.
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
> drivers/base/core.c | 12 ++++++++----
> include/linux/fwnode.h | 13 +++++++++----
> 2 files changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 48cd43a91ce6..e6d3e6d485da 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -2297,7 +2297,7 @@ int device_add(struct device *dev)
> struct device *parent;
> struct kobject *kobj;
> struct class_interface *class_intf;
> - int error = -EINVAL;
> + int error = -EINVAL, fw_ret;
> struct kobject *glue_dir = NULL;
>
> dev = get_device(dev);
> @@ -2413,9 +2413,13 @@ int device_add(struct device *dev)
> */
> device_link_add_missing_supplier_links();
>
> - if (fwnode_has_op(dev->fwnode, add_links)
> - && fwnode_call_int_op(dev->fwnode, add_links, dev))
> - device_link_wait_for_mandatory_supplier(dev, true);
> + if (fwnode_has_op(dev->fwnode, add_links)) {
fw_ret can be defined here and I'd just call it "ret".
> + fw_ret = fwnode_call_int_op(dev->fwnode, add_links, dev);
> + if (fw_ret == -ENODEV)
> + device_link_wait_for_mandatory_supplier(dev);
> + else if (fw_ret)
> + device_link_wait_for_optional_supplier(dev);
> + }
>
> bus_probe_device(dev);
> if (parent)
> diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
> index 25bb81f8ded8..a19134eae5a5 100644
> --- a/include/linux/fwnode.h
> +++ b/include/linux/fwnode.h
> @@ -96,10 +96,15 @@ struct fwnode_reference_args {
> * available suppliers.
> *
> * Return 0 if device links have been successfully created to all
> - * the suppliers of this device or if the supplier information is
> - * not known. Return an error if and only if the supplier
> - * information is known but some of the suppliers are not yet
> - * available to create device links to.
> + * the suppliers this device needs to create device links to or if
> + * the supplier information is not known.
"the known suppliers of this device or if the supplier information is not known."
> + *
> + * Return -ENODEV if and only if the suppliers needed for probing
> + * the device are not yet available to create device links to.
It would be more precise to say something like this:
"Return -ENODEV if an attempt to create a device link to one of the device's
suppliers needed for probing it fails."
> + *
> + * Return -EAGAIN if there are suppliers that need to be linked to
> + * that are not yet available but none of those suppliers are
> + * necessary for probing this device.
"Return -EAGAIN if attempts to create device links to some of the device's
suppliers have failed, but those suppliers are not necessary for probing the
device."
> */
> struct fwnode_operations {
> struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
>
next prev parent reply other threads:[~2019-11-05 22:43 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 22:00 [PATCH v1 0/5] Improve of_devlink to handle "proxy cycles" Saravana Kannan
2019-10-28 22:00 ` [PATCH v1 1/5] driver core: Add device link support for SYNC_STATE_ONLY flag Saravana Kannan
2019-10-28 22:00 ` [PATCH v1 2/5] driver core: Allow a device to wait on optional suppliers Saravana Kannan
2019-11-05 22:29 ` Rafael J. Wysocki
2019-11-05 22:35 ` Saravana Kannan
2019-11-08 0:05 ` Rafael J. Wysocki
2019-11-08 0:08 ` Saravana Kannan
2019-10-28 22:00 ` [PATCH v1 3/5] driver core: Allow fwnode_operations.add_links to differentiate errors Saravana Kannan
2019-11-05 22:43 ` Rafael J. Wysocki [this message]
2019-11-05 22:52 ` Saravana Kannan
2019-11-05 23:07 ` Rafael J. Wysocki
2019-11-06 0:00 ` Saravana Kannan
2019-11-08 0:35 ` Rafael J. Wysocki
2019-11-13 2:06 ` Saravana Kannan
2019-10-28 22:00 ` [PATCH v1 4/5] of: property: Make sure child dependencies don't block probing of parent Saravana Kannan
2019-11-04 17:01 ` Rob Herring
2019-11-04 19:04 ` Saravana Kannan
2019-10-28 22:00 ` [PATCH v1 5/5] of: property: Skip adding device links to suppliers that aren't devices Saravana Kannan
2019-11-04 15:18 ` Rob Herring
2019-11-04 19:01 ` Saravana Kannan
2019-11-04 19:14 ` Rob Herring
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