On Sun, Dec 15, 2019 at 10:27:46AM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.19-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 bd82873f23c9a6ad834348f8b83f3b6a5bca2c65 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Date: Wed, 11 Dec 2019 16:20:07 +0200
Subject: [PATCH] xhci: make sure interrupts are restored to correct state
spin_unlock_irqrestore() might be called with stale flags after
reading port status, possibly restoring interrupts to a incorrect
state.
If a usb2 port just finished resuming while the port status is read
the spin lock will be temporary released and re-acquired in a separate
function. The flags parameter is passed as value instead of a pointer,
not updating flags properly before the final spin_unlock_irqrestore()
is called.
Cc: <stable@xxxxxxxxxxxxxxx> # v3.12+
Fixes: 8b3d45705e54 ("usb: Fix xHCI host issues on remote wakeup.")
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191211142007.8847-7-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
There were quite a few code movements around this:
e67ebf1b3815 ("xhci: move usb2 get port status link resume handling to its own function")
5f78a54f8d31 ("xhci: move usb3 speficic bits to own function in get_port_status call")
70e9b53dfedc ("xhci: move usb2 speficic bits to own function in get_port_status call")
I've fixed up the original patch to work around that and queued for 4.19
- 4.4.
--
Thanks,
Sasha
