[PATCH v2 00/11] fw_devlink improvements

Saravana Kannan
2023-01-27T00:11:50Z

This patch series improves fw_devlink in the following ways:

1. It no longer cares about a fwnode having a "compatible" property. It
figures this our more dynamically. The only expectation is that
fwnode that are converted to devices actually get probed by a driver
for the dependencies to be enforced correctly.

2. Finer grained dependency tracking. fw_devlink will now create device
links from the consumer to the actual resource's device (if it has one,
Eg: gpio_device) instead of the parent supplier device. This improves
things like async suspend/resume ordering, potentially remove the need
for frameworks to create device links, more parallelized async probing,
and better sync_state() tracking.

3. Handle hardware/software quirks where a child firmware node gets
populated as a device before its parent firmware node AND actually
supplies a non-optional resource to the parent firmware node's
device.

4. Way more robust at cycle handling (see patch for the insane cases).

5. Stops depending on OF_POPULATED to figure out some corner cases.

6. Simplifies the work that needs to be done by the firmware specific
code.

Sorry it took a while to roll in the fixes I gave in the v1 series
thread[1] into a v2 series.

Since I didn't make any additional changes on top of what I already gave
in the v1 thread and Dmitry is very eager to get this series going, I'm
sending it out without testing locally. I already tested these patches a
few months ago as part of the v1 series. So I don't expect any major
issues. I'll test them again on my end in the next few days and will
report here if I actually find anything wrong.

Tony, Naresh, Abel, Sudeep, Geert,

I got the following reviewed by's and tested by's a few months back, but
it's been 5 months since I sent out v1. So I wasn't sure if it was okay
to include them in the v2 commits. Let me know if you are okay with this
being included in the commits and/or if you want to test this series
again.

Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Abel Vesa <abel.vesa@linaro.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Dmitry, Maxim(s), Miquel, Luca, Doug, Colin, Martin, Jean-Philippe,

I've Cc-ed you because I had pointed you to v1 of this series + the
patches in that thread at one point or another as a fix to some issue
you were facing. It'd appreciate it if you can test this series and
report any issues, or things it fixed and give Tested-bys.

In addition, if you can also apply a revert of this series[2] and delete
driver_deferred_probe_check_state() from your tree and see if you hit
any issues and report them, that'd be great too! I'm pretty sure some of
you will hit issues with that. I want to fix those next and then
revert[2].

Thanks,
Saravana

[1] - https://lore.kernel.org/lkml/20220810060040.321697-1-saravanak@google.com/
[2] - https://lore.kernel.org/lkml/20220819221616.2107893-1-saravanak@google.com/
[3] - https://lore.kernel.org/lkml/CAGETcx-JUV1nj8wBJrTPfyvM7=Mre5j_vkVmZojeiumUGG6QZQ@mail.gmail.com/

v1 -> v2:
- Fixed Patch 1 to handle a corner case discussed in [3].
- New patch 10 to handle "fsl,imx8mq-gpc" being initialized by 2 drivers.
- New patch 11 to add fw_devlink support for SCMI devices.

Cc: Abel Vesa <abel.vesa@linaro.org>
Cc: Alexander Stein <alexander.stein@ew.tq-group.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: John Stultz <jstultz@google.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Maxim Kiselev <bigunclemax@gmail.com>
Cc: Maxim Kochetkov <fido_max@inbox.ru>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Luca Weiss <luca.weiss@fairphone.com>
Cc: Colin Foster <colin.foster@in-advantage.com>
Cc: Martin Kepplinger <martin.kepplinger@puri.sm>
Cc: Jean-Philippe Brucker <jpb@kernel.org>

Saravana Kannan (11):
driver core: fw_devlink: Don't purge child fwnode's consumer links
driver core: fw_devlink: Improve check for fwnode with no
device/driver
soc: renesas: Move away from using OF_POPULATED for fw_devlink
gpiolib: Clear the gpio_device's fwnode initialized flag before adding
driver core: fw_devlink: Add DL_FLAG_CYCLE support to device links
driver core: fw_devlink: Allow marking a fwnode link as being part of
a cycle
driver core: fw_devlink: Consolidate device link flag computation
driver core: fw_devlink: Make cycle detection more robust
of: property: Simplify of_link_to_phandle()
irqchip/irq-imx-gpcv2: Mark fwnode device as not initialized
firmware: arm_scmi: Set fwnode for the scmi_device

drivers/base/core.c | 443 +++++++++++++++++++++-----------
drivers/firmware/arm_scmi/bus.c | 2 +
drivers/gpio/gpiolib.c | 6 +
drivers/irqchip/irq-imx-gpcv2.c | 1 +
drivers/of/property.c | 84 +-----
drivers/soc/imx/gpcv2.c | 1 +
drivers/soc/renesas/rcar-sysc.c | 2 +-
include/linux/device.h | 1 +
include/linux/fwnode.h | 12 +-
9 files changed, 332 insertions(+), 220 deletions(-)

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2.39.1.456.gfc5497dd1b-goog