[PATCH v1 0/9] fw_devlink improvements

Saravana Kannan
2022-08-10T06:01:25Z

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.

This took way too long to get done due to typo bugs I had in my rewrite or
corner cases I had to find and handle. But it's fairly well tested at this
point and I expect this to work properly.

Abel & Doug,

This should fix your cyclic dependency issues with your display. Can you
give it a shot please?

Alexander,

This should fix your issue where the power domain device not having a
compatible property. Can you give it a shot please?

Tony,

This should handle the odd case of the child being the supplier of the
parent. Can you please give this a shot? I want to make sure the cycle
detection code handles this properly and treats it like it's NOT a cycle.

Geert,

Can you test the renesas stuff I changed please? They should continue
working like before. Any other sanity test on other hardware would be
great too.

Sudeep,

I don't think there are any unfixed issues you had reported in my other
patches that this series might fix, but it'll be nice if you could give
this a sanity test.

Guenter,

I don't think this will fix the issue you reported in the amba patch, but
it's worth a shot because it improves a bunch of corner case handling. So
it might be better at handling whatever corner cases you might have in the
qemu platforms.

Thanks,
Saravana

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>

Saravana Kannan (9):
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()

drivers/base/core.c | 437 +++++++++++++++++++++-----------
drivers/gpio/gpiolib.c | 6 +
drivers/of/property.c | 84 +-----
drivers/soc/renesas/rcar-sysc.c | 2 +-
include/linux/device.h | 1 +
include/linux/fwnode.h | 12 +-
6 files changed, 323 insertions(+), 219 deletions(-)

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2.37.1.559.g78731f0fdb-goog