usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm
authorMathias Nyman <mathias.nyman@linux.intel.com>
Thu, 26 Jun 2025 13:01:02 +0000 (16:01 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 26 Jun 2025 14:57:39 +0000 (15:57 +0100)
commita49e1e2e785fb3621f2d748581881b23a364998a
treeaf51c4e4285d1669ebe9f9f7edcdd9ed24215f08
parent099cf1fbb8afc3771f408109f62bdec66f85160e
usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm

Delayed work to prevent USB3 hubs from runtime-suspending immediately
after resume was added in commit 8f5b7e2bec1c ("usb: hub: fix detection
of high tier USB3 devices behind suspended hubs").

This delayed work needs be flushed if system suspends, or hub needs to
be quiesced for other reasons right after resume. Not flushing it
triggered issues on QC SC8280XP CRD board during suspend/resume testing.

Fix it by flushing the delayed resume work in hub_quiesce()

The delayed work item that allow hub runtime suspend is also scheduled
just before calling autopm get. Alan pointed out there is a small risk
that work is run before autopm get, which would call autopm put before
get, and mess up the runtime pm usage order.
Swap the order of work sheduling and calling autopm get to solve this.

Cc: stable <stable@kernel.org>
Fixes: 8f5b7e2bec1c ("usb: hub: fix detection of high tier USB3 devices behind suspended hubs")
Reported-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Closes: https://lore.kernel.org/linux-usb/acaaa928-832c-48ca-b0ea-d202d5cd3d6c@oss.qualcomm.com
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Closes: https://lore.kernel.org/linux-usb/c73fbead-66d7-497a-8fa1-75ea4761090a@rowland.harvard.edu
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250626130102.3639861-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c