On Thu, May 27, 2021 at 10:45:34AM -0500, Mario Limonciello wrote:

The XHCI controller is required to enter D3hot rather than D3cold for AMD
s2idle on this hardware generation.

Otherwise, the 'Controller Not Ready' (CNR) bit is not being cleared by
host in resume and eventually this results in xhci resume failures during
the s2idle wakeup.

Suggested-by: Prike Liang <redacted>
Link: https://lore.kernel.org/linux-usb/1612527609-7053-1-git-send-email-Prike.Liang@amd.com/ (local)
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/usb/host/xhci-pci.c | 7 ++++++-
 drivers/usb/host/xhci.h     | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

Should it go to stable kernels, and if so, how far back?

thanks,

greg k-h