From: Saravana Kannan <saravanak@google.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ard Biesheuvel <ardb@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Marc Zyngier <maz@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Tomi Valkeinen <tomi.valkeinen@ti.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Grygorii Strashko <grygorii.strashko@ti.com>,
"Cc: Android Kernel" <kernel-team@android.com>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-efi <linux-efi@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: Re: [PATCH v1 17/18] driver core: Add helper functions to convert fwnode links to device links
Date: Fri, 20 Nov 2020 18:00:43 -0800 [thread overview]
Message-ID: <CAGETcx-nbUVm5LL9n0Ee=p6GV-b0r048S56zWJ6e_Fd421krjA@mail.gmail.com> (raw)
In-Reply-To: <CAJZ5v0gALooTYTLr9JOynHTT=Bqvzp1iTdpQ+SfQn+2u__w-0w@mail.gmail.com>
On Mon, Nov 16, 2020 at 8:57 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Thu, Nov 5, 2020 at 12:24 AM Saravana Kannan <saravanak@google.com> wrote:
> >
> > Add helper functions __fw_devlink_link_to_consumers() and
> > __fw_devlink_link_to_suppliers() that convert fwnode links to device
> > links.
> >
> > __fw_devlink_link_to_consumers() is for creating:
> > - Device links between a newly added device and all its consumer devices
> > that have been added to driver core.
> > - Proxy SYNC_STATE_ONLY device links between the newly added device and
> > the parent devices of all its consumers that have not been added to
> > driver core yet.
> >
> > __fw_devlink_link_to_suppliers() is for creating:
> > - Device links between a newly added device and all its supplier devices
> > - Proxy SYNC_STATE_ONLY device links between the newly added device and
> > all the supplier devices of its child device nodes.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > ---
> > drivers/base/core.c | 228 ++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 228 insertions(+)
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index d51dd564add1..0c87ff949d81 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -1585,6 +1585,234 @@ static struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode)
> > return dev;
> > }
> >
> > +/**
> > + * fw_devlink_create_devlink - Create a device link from a consumer to fwnode
>
> Have you considered renaming "fw_devlink" to "fwnode_link"?
I avoided using fwnode_link prefix because it's not related to the
fwnode link APIs. This is a fw_devlink feature related code and hence
the fw_devlink prefix.
I could just call it fw_devlink_create() or fw_devlink_create_links()
or fwnode_to_dev_link() if that's less confusing. Any preferences?
> That would be much less confusing IMO and the name of this function
> would be clearer.
>
> > + * @con - Consumer device for the device link
> > + * @sup - fwnode handle of supplier
> > + *
> > + * This function will try to create a device link between the consumer and the
> > + * supplier devices.
>
> "... between consumer device @con and the supplier device represented
> by @sup" (and see below).
>
> > + *
> > + * The supplier has to be provided as a fwnode because incorrect cycles in
> > + * fwnode links can sometimes cause the supplier device to never be created.
> > + * This function detects such cases and returns an error if a device link being
> > + * created in invalid.
>
> "... returns an error if it cannot create a device link from the
> consumer to a missing supplier."
>
> > + *
> > + * Returns,
> > + * 0 on successfully creating a device link
> > + * -EINVAL if the device link being attempted is invalid
>
> "if the device link cannot be created as expected"
>
> > + * -EAGAIN if the device link needs to be attempted again in the future
>
> "if the device link cannot be created right now, but it may be
> possible to do that in the future."
Ack to all the documentation comments above.
>
> > + */
> > +static int fw_devlink_create_devlink(struct device *con,
> > + struct fwnode_handle *sup, u32 flags)
>
> I'd call the second arg sup_handle to indicate that it is not a struct device.
Ack
>
> > +{
> > + struct device *sup_dev, *sup_par_dev;
> > + int ret = 0;
> > +
> > + sup_dev = get_dev_from_fwnode(sup);
> > + /*
> > + * If we can't find the supplier device from its fwnode, it might be
> > + * due to a cyclic dependcy between fwnodes. Some of these cycles can
>
> dependency
>
Ack
> > + * be broken by applying logic. Check for these types of cycles and
> > + * break them so that devices in the cycle probe properly.
> > + */
>
> I would do
>
> if (sup_dev) {
> if (!device_link_add(con, sup_dev, flags))
> ret = -EINVAL;
>
> put_device(sup_dev);
> return ret;
> }
>
> here and the cycle detection (error code path) below, possibly using
> the same dev pointer.
Nice suggestion, thanks!
-Saravana
next prev parent reply other threads:[~2020-11-21 2:01 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-04 23:23 [PATCH v1 00/18] Refactor fw_devlink to significantly improve boot time Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 01/18] Revert "driver core: Avoid deferred probe due to fw_devlink_pause/resume()" Saravana Kannan
2020-11-05 9:34 ` Greg Kroah-Hartman
2020-11-05 23:19 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 02/18] Revert "driver core: Rename dev_links_info.defer_sync to defer_hook" Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 03/18] Revert "driver core: Don't do deferred probe in parallel with kernel_init thread" Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 04/18] Revert "driver core: Remove check in driver_deferred_probe_force_trigger()" Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 05/18] Revert "of: platform: Batch fwnode parsing when adding all top level devices" Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 06/18] Revert "driver core: fw_devlink: Add support for batching fwnode parsing" Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 07/18] driver core: Add fwnode_init() Saravana Kannan
2020-11-05 9:36 ` Greg Kroah-Hartman
2020-11-05 23:20 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 08/18] driver core: Add fwnode link support Saravana Kannan
2020-11-16 15:51 ` Rafael J. Wysocki
2020-11-21 1:59 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 09/18] driver core: Allow only unprobed consumers for SYNC_STATE_ONLY device links Saravana Kannan
2020-11-16 15:57 ` Rafael J. Wysocki
2020-11-21 1:59 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 10/18] device property: Add fwnode_is_ancestor_of() Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 11/18] driver core: Redefine the meaning of fwnode_operations.add_links() Saravana Kannan
2020-11-16 16:16 ` Rafael J. Wysocki
2020-11-21 1:59 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 12/18] driver core: Add fw_devlink_parse_fwtree() Saravana Kannan
2020-11-16 16:25 ` Rafael J. Wysocki
2020-11-21 2:00 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 13/18] driver core: Add fwnode_get_next_parent_dev() helper function Saravana Kannan
2020-11-16 16:27 ` Rafael J. Wysocki
2020-11-21 2:00 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 14/18] driver core: Use device's fwnode to check if it is waiting for suppliers Saravana Kannan
2020-11-16 16:34 ` Rafael J. Wysocki
2020-11-21 2:00 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 15/18] of: property: Update implementation of add_links() to create fwnode links Saravana Kannan
2020-11-05 9:42 ` Greg Kroah-Hartman
2020-11-05 23:25 ` Saravana Kannan
2020-11-06 1:24 ` Saravana Kannan
2020-11-06 7:22 ` Greg Kroah-Hartman
2020-11-06 7:41 ` Saravana Kannan
2020-11-06 7:51 ` Greg Kroah-Hartman
2020-11-06 8:29 ` Saravana Kannan
2020-11-04 23:23 ` [PATCH v1 16/18] efi: " Saravana Kannan
2020-11-05 9:43 ` Greg Kroah-Hartman
2020-11-05 23:27 ` Saravana Kannan
2020-11-06 6:45 ` Greg Kroah-Hartman
2020-11-04 23:23 ` [PATCH v1 17/18] driver core: Add helper functions to convert fwnode links to device links Saravana Kannan
2020-11-05 9:43 ` Greg Kroah-Hartman
2020-11-05 23:32 ` Saravana Kannan
2020-11-06 7:24 ` Greg Kroah-Hartman
2020-11-06 7:43 ` Saravana Kannan
2020-11-16 16:57 ` Rafael J. Wysocki
2020-11-21 2:00 ` Saravana Kannan [this message]
2020-11-04 23:23 ` [PATCH v1 18/18] driver core: Refactor fw_devlink feature Saravana Kannan
2020-11-04 23:26 ` [PATCH v1 00/18] Refactor fw_devlink to significantly improve boot time Saravana Kannan
2020-11-06 5:09 ` Laurent Pinchart
2020-11-06 8:36 ` Saravana Kannan
2020-11-06 12:46 ` Grygorii Strashko
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