[PATCH v3 00/12] fw_devlink improvements

Wed Feb 15 19:12:09 PST 2023

On 07/02/2023 03:41, Saravana Kannan wrote:
> Naresh, Tony, Abel, Geert, Dmitry, Maxim(s), Miquel, Luca, Doug, Martin,
> Jean-Philippe,
>
> Can I get your Tested-by's for this v3 series please?
>
> Vladimir,
>
> Ccing you because DSA's and fw_devlink have known/existing problems
> (still in my TODOs to fix). But I want to make sure this series doesn't
> cause additional problems for DSA.
>
> All,
>
> 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 out more dynamically. The only expectation is that
>     fwnodes 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.
>
> The v3 series has gone through my usual testing on my end and looks good
> to me.

Saravana,

Please excuse me, I was completely overwhelmed with my regular work and
had no time to properly test the series, while doing just the light
test would defeat the purpose of testing.

Tested-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org> # Qualcomm RB3

Thanks a lot for going through all the troubles and hunting all the issues!

Just a note: on an RB3 device (arm64 qcom/sdm845-db845c.dtsi) extended
with the patch at [3] I got the following messages in dmesg:

[    1.051325] platform ae00000.mdss: Failed to create device link
with ae00000.mdss
[    1.059368] platform ae00000.mdss: Failed to create device link
with ae00000.mdss
[    1.067174] platform ae00000.mdss: Failed to create device link
with ae00000.mdss
[    1.088322] platform c440000.spmi: Failed to create device link
with c440000.spmi
[    1.096019] platform c440000.spmi: Failed to create device link
with c440000.spmi
[    1.103707] platform c440000.spmi: Failed to create device link
with c440000.spmi
[    1.111400] platform c440000.spmi: Failed to create device link
with c440000.spmi
[    1.119141] platform c440000.spmi: Failed to create device link
with c440000.spmi
[    1.126825] platform c440000.spmi: Failed to create device link
with c440000.spmi
[    2.024763] qcom-lab-ibb-regulator c440000.spmi:pmic at 3:labibb:
Failed to create device link with c440000.spmi
[    2.035026] qcom-lab-ibb-regulator c440000.spmi:pmic at 3:labibb:
Failed to create device link with c440000.spmi

They look to be harmless, but it might be good to filter some of them
out? Especially the ones which tell about creating a device link
pointing back to the same device.

[3] https://lore.kernel.org/linux-arm-msm/20230118082048.2198715-1-dmitry.baryshkov@linaro.org/

>
> Thanks,
> Saravana
>
> [1] - https://lore.kernel.org/lkml/20220810060040.321697-1-saravanak@google.com/
> [2] - https://lore.kernel.org/lkml/CAGETcx-JUV1nj8wBJrTPfyvM7=Mre5j_vkVmZojeiumUGG6QZQ@mail.gmail.com/
>
> v1 -> v2:
> - Fixed Patch 1 to handle a corner case discussed in [2].
> - New patch 10 to handle "fsl,imx8mq-gpc" being initialized by 2 drivers.
> - New patch 11 to add fw_devlink support for SCMI devices.
>
> v2 -> v3:
> - Addressed most of Andy's comments in v2
> - Added Colin and Sudeep's Tested-by for the series (except the imx and
>    renesas patches)
> - Added Sudeep's Acked-by for the scmi patch.
> - Added Geert's Reviewed-by for the renesas patch.
> - Fixed gpiolib crash reported by Naresh.
> - Patch 6: Fix __fwnode_links_move_consumers() to preserve fwnode link flags.
> - New Patch 12 to fix nvmem-cells issue reported by Maxim(s)/Miquel.
> - Deleted some stale function doc in Patch 8
>
> Cc: Abel Vesa <abel.vesa at linaro.org>
> Cc: Alexander Stein <alexander.stein at ew.tq-group.com>
> Cc: Tony Lindgren <tony at atomide.com>
> Cc: Sudeep Holla <sudeep.holla at arm.com>
> Cc: Geert Uytterhoeven <geert at linux-m68k.org>
> Cc: John Stultz <jstultz at google.com>
> Cc: Doug Anderson <dianders at chromium.org>
> Cc: Guenter Roeck <linux at roeck-us.net>
> Cc: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> Cc: Maxim Kiselev <bigunclemax at gmail.com>
> Cc: Maxim Kochetkov <fido_max at inbox.ru>
> Cc: Miquel Raynal <miquel.raynal at bootlin.com>
> Cc: Luca Weiss <luca.weiss at fairphone.com>
> Cc: Colin Foster <colin.foster at in-advantage.com>
> Cc: Martin Kepplinger <martin.kepplinger at puri.sm>
> Cc: Jean-Philippe Brucker <jpb at kernel.org>
> Cc: Vladimir Oltean <vladimir.oltean at nxp.com>
>
> Saravana Kannan (12):
>    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
>    mtd: mtdpart: Don't create platform device that'll never probe
>
>   drivers/base/core.c             | 449 +++++++++++++++++++++-----------
>   drivers/firmware/arm_scmi/bus.c |   3 +-
>   drivers/gpio/gpiolib.c          |   7 +
>   drivers/irqchip/irq-imx-gpcv2.c |   1 +
>   drivers/mtd/mtdpart.c           |  10 +
>   drivers/of/property.c           |  84 +-----
>   drivers/soc/imx/gpcv2.c         |   2 +-
>   drivers/soc/renesas/rcar-sysc.c |   2 +-
>   include/linux/device.h          |   1 +
>   include/linux/fwnode.h          |  12 +-
>   10 files changed, 344 insertions(+), 227 deletions(-)
>

--
With best wishes

Dmitry