This is a note to let you know that I've just added the patch titled
xhci: Do warm-reset when both CAS and XDEV_RESUME are set
to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 904df64a5f4d5ebd670801d869ca0a6d6a6e8df6 Mon Sep 17 00:00:00 2001
From: Kai-Heng Feng kai.heng.feng@canonical.com Date: Fri, 21 Aug 2020 12:15:48 +0300 Subject: xhci: Do warm-reset when both CAS and XDEV_RESUME are set
Sometimes re-plugging a USB device during system sleep renders the device useless: [ 173.418345] xhci_hcd 0000:00:14.0: Get port status 2-4 read: 0x14203e2, return 0x10262 ... [ 176.496485] usb 2-4: Waited 2000ms for CONNECT [ 176.496781] usb usb2-port4: status 0000.0262 after resume, -19 [ 176.497103] usb 2-4: can't resume, status -19 [ 176.497438] usb usb2-port4: logical disconnect
Because PLS equals to XDEV_RESUME, xHCI driver reports U3 to usbcore, despite of CAS bit is flagged.
So proritize CAS over XDEV_RESUME to let usbcore handle warm-reset for the port.
Cc: stable stable@vger.kernel.org Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20200821091549.20556-3-mathias.nyman@linux.intel.c... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/xhci-hub.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index c3554e37e09f..4e14e164cb68 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -740,15 +740,6 @@ static void xhci_hub_report_usb3_link_state(struct xhci_hcd *xhci, { u32 pls = status_reg & PORT_PLS_MASK;
- /* resume state is a xHCI internal state. - * Do not report it to usb core, instead, pretend to be U3, - * thus usb core knows it's not ready for transfer - */ - if (pls == XDEV_RESUME) { - *status |= USB_SS_PORT_LS_U3; - return; - } - /* When the CAS bit is set then warm reset * should be performed on port */ @@ -770,6 +761,16 @@ static void xhci_hub_report_usb3_link_state(struct xhci_hcd *xhci, */ pls |= USB_PORT_STAT_CONNECTION; } else { + /* + * Resume state is an xHCI internal state. Do not report it to + * usb core, instead, pretend to be U3, thus usb core knows + * it's not ready for transfer. + */ + if (pls == XDEV_RESUME) { + *status |= USB_SS_PORT_LS_U3; + return; + } + /* * If CAS bit isn't set but the Port is already at * Compliance Mode, fake a connection so the USB core