Re: [PATCH v3] PCI: rcar-gen4: Add missing PM ops

From: Marek Vasut

Date: Tue Sep 22 2026 - 13:59:01 EST


On 9/22/26 4:28 PM, Manivannan Sadhasivam wrote:
On Mon, Sep 07, 2026 at 06:35:22PM +0200, Marek Vasut wrote:
The R-Car Gen4 PCIe controller is part of a power domain. On R-Car S4
and V4H, this is an always-on power domain which is not shut down in
suspend. On R-Car V4M, this is a dedicated A2PCIPHY power domain,
which is shut down during suspend, and the controller loses state,
which prevents the PCIe from working after resume.

Fix this by adding generic suspend/resume noirq ops for the controller,
which tear the link down on suspend, and restart it on resume. Use the
same PM ops on all of R-Car Gen4 to gracefully suspend and resume the
PCIe link on V4H and S4 too.

Test case which demonstrates the problem on R-Car V4M:
"
$ hexdump -vC /sys/bus/pci/devices/0000:00:00.0/config > /tmp/pre
$ echo s2idle > /sys/power/mem_sleep
$ echo platform > /sys/power/pm_test
$ echo mem > /sys/power/state
$ hexdump -vC /sys/bus/pci/devices/0000:00:00.0/config > /tmp/post
$ diff -Naru /tmp/pre /tmp/post
...
-00000000 12 19 32 00 07 05 10 00 00 00 04 06 00 00 01 00
+00000000 12 19 32 00 07 05 10 00 00 00 00 ff 00 00 80 00
^^^^^
Class 0604->00ff
"

Fixes: 0d0c551011df ("PCI: rcar-gen4: Add R-Car Gen4 PCIe controller support for host mode")
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>

This patch doesn't apply even after applying [1]. Please rebase on top of
pci/controller/dwc-rcar-gen4 branch and repost.
Rebased, retested and V4 submitted. Thanks !