Re: [PATCH 4.14 105/136] usb/ehci-platform: Set PM runtime as active on resume

Hi Eugeniu

On 07/09/20 09:00, Eugeniu Rosca wrote:

Hello everyone,

Cc: linux-renesas-soc Cc: linux-pm

[...]

After integrating v4.14.186 commit 5410d158ca2a50 ("usb/ehci-platform: Set PM runtime as active on resume") into downstream v4.14.x, we started to consistently experience below panic [1] on every second s2ram of R-Car H3 Salvator-X Renesas reference board.

After some investigations, we concluded the following:

• the issue does not exist in vanilla v5.8-rc4+
• [bisecting shows that] the panic on v4.14.186 is caused by the lack of v5.6-rc1 commit 987351e1ea7772 ("phy: core: Add consumer device link support"). Getting evidence for that is easy. Reverting 987351e1ea7772 in vanilla leads to a similar backtrace [2].

Questions:

• Backporting 987351e1ea7772 ("phy: core: Add consumer device link support") to v4.14.187 looks challenging enough, so probably not worth it. Anybody to contradict this?
• Assuming no plans to backport the missing mainline commit to v4.14.x, should the following three v4.14.186 commits be reverted on v4.14.x?
  • baef809ea497a4 ("usb/ohci-platform: Fix a warning when hibernating")
  • 9f33eff4958885 ("usb/xhci-plat: Set PM runtime as active on resume")
  • 5410d158ca2a50 ("usb/ehci-platform: Set PM runtime as active on resume")

Thanks for investigating this.

Alan, Greg, do you have any ideas?

Let me know if there's anything I can help with.

Thanks

-- Qais Yousef