Hi Saravana,

On 04.02.2021 22:31, Saravana Kannan wrote:

On Thu, Feb 4, 2021 at 3:52 AM Marek Szyprowski
[off-list ref] wrote:

quoted

On 21.01.2021 23:57, Saravana Kannan wrote:

quoted

This allows fw_devlink to create device links between consumers of an
interrupt and the supplier of the interrupt.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Thierry Reding <redacted>
Reviewed-by: Linus Walleij <redacted>
Signed-off-by: Saravana Kannan <redacted>

This patch landed some time ago in linux-next as commit 4104ca776ba3
("of: property: Add fw_devlink support for interrupts"). It breaks MMC
host controller operation on ARM Juno R1 board (the mmci@50000 device
defined in arch/arm64/boot/dts/arm/juno-motherboard.dtsi). I didn't

I grepped around and it looks like the final board file is this or
whatever includes it?
arch/arm64/boot/dts/arm/juno-base.dtsi

The final board file is arch/arm64/boot/dts/arm/juno-r1.dts

This patch just finds the interrupt-parent and then tries to use that
as a supplier if "interrupts" property is listed. But the only
interrupt parent I can see is:
         gic: interrupt-controller@2c010000 {
                 compatible = "arm,gic-400", "arm,cortex-a15-gic";

And the driver uses IRQCHIP_DECLARE() and hence should be pretty much
a NOP since those suppliers are never devices and are ignored.
$ git grep "arm,gic-400" -- drivers/
drivers/irqchip/irq-gic.c:IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);

This doesn't make any sense. Am I looking at the right files? Am I
missing something?

Okay, I've added displaying a list of deferred devices when mounting 
rootfs fails and got following items:

Deferred devices:
18000000.ethernet        platform: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
1c050000.mmci    amba: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
1c1d0000.gpio    amba: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
2b600000.iommu   platform: probe deferral - wait for supplier 
scpi-power-domains
7ff50000.hdlcd   platform: probe deferral - wait for supplier scpi-clk
7ff60000.hdlcd   platform: probe deferral - wait for supplier scpi-clk
1c060000.kmi     amba: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
1c070000.kmi     amba: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
1c170000.rtc     amba: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
1c0f0000.wdt     amba: probe deferral - supplier 
bus@8000000:motherboard-bus not ready
gpio-keys
Kernel panic - not syncing: VFS: Unable to mount root fs on 
unknown-block(0,0)

I don't see the 'bus@8000000:motherboard-bus' on the deferred devices 
list, so it looks that device core added a link to something that is not 
a platform device...

Best regards

-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland