The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 4f190e0b9de89c4c917c3ffb3799e9d00fc534ac Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan@xxxxxxxxxx> Date: Mon, 9 Oct 2017 22:46:07 -0500 Subject: [PATCH] USB: musb: fix session-bit runtime-PM quirk The current session-bit quirk implementation does not prevent the retry counter from underflowing, something which could break runtime PM and keep the device active for a very long time (about 2^32 seconds) after a disconnect. This notably breaks the B-device timeout case, but could potentially cause problems also when the controller is operating as an A-device. Fixes: 2bff3916fda9 ("usb: musb: Fix PM for hub disconnect") Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.9 Cc: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Tested-by: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Bin Liu <b-liu@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index 029692053dd3..07b8c7152e3d 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -1861,22 +1861,22 @@ static void musb_pm_runtime_check_session(struct musb *musb) MUSB_DEVCTL_HR; switch (devctl & ~s) { case MUSB_QUIRK_B_INVALID_VBUS_91: - if (musb->quirk_retries--) { + if (musb->quirk_retries) { musb_dbg(musb, "Poll devctl on invalid vbus, assume no session"); schedule_delayed_work(&musb->irq_work, msecs_to_jiffies(1000)); - + musb->quirk_retries--; return; } /* fall through */ case MUSB_QUIRK_A_DISCONNECT_19: - if (musb->quirk_retries--) { + if (musb->quirk_retries) { musb_dbg(musb, "Poll devctl on possible host mode disconnect"); schedule_delayed_work(&musb->irq_work, msecs_to_jiffies(1000)); - + musb->quirk_retries--; return; } if (!musb->session)