Messages in this thread | | | Subject | Re: [PATCH 1/2] usb: xhci: fix uninitialized completion when USB3 port got wrong status | From | Mathias Nyman <> | Date | Tue, 23 Oct 2018 13:39:43 +0300 |
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On 22.10.2018 20:53, Aaron Ma wrote: > > > On 10/22/18 9:12 PM, Mathias Nyman wrote: >> On 21.10.2018 20:08, Aaron Ma wrote: >>> Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on >>> Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3, >>> after clear port reset it works fine. >>> >>> Since this device is registered on USB3 roothub at boot, >>> when port status reports not superspeed, xhci_get_port_status will call >>> an uninitialized completion in bus_state[0]. >>> Kernel will hang because of NULL pointer. >>> >>> Restrict the USB2 resume status check in USB2 roothub to fix hang issue. >>> No harm to initialize USB3 bus_state[0] in case it is called. >>> >>> Signed-off-by: Aaron Ma <aaron.ma@canonical.com> >>> --- >>> drivers/usb/host/xhci-hub.c | 2 +- >>> drivers/usb/host/xhci-mem.c | 1 >>> drivers/usb/host/xhci-ring.c | 2 +- >>> 3 files changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c >>> index 7e2a531ba321..d30ca6ceffc9 100644 >>> --- a/drivers/usb/host/xhci-hub.c >>> +++ b/drivers/usb/host/xhci-hub.c >>> @@ -876,7 +876,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd, >>> status |= USB_PORT_STAT_SUSPEND; >>> } >>> if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME && >>> - !DEV_SUPERSPEED_ANY(raw_port_status)) { >>> + !DEV_SUPERSPEED_ANY(raw_port_status) && 1 == hcd_index(hcd)) { >>> if ((raw_port_status & PORT_RESET) || >>> !(raw_port_status & PORT_PE)) >>> return 0xffffffff; >> >> The original !DEV_SUPERSPEED_ANY() check was not suitable here. >> It checks the port-speed field of portsc register (bits 13:10), which >> are only valid for USB3 >> ports if all link training is done and port reached its "enabled" state. >> Otherwise it will return 0, and USB3 ports may be mistaken for USB2 ports. > > PORT_ENABLE should be already set to one. > The same device ID card reader doesn't have issue on Sunrise Point. > Maybe it is related to Cannon lake PCH USB controller? >
Ok, thanks for the info
> > V2 sent out. Cc-ed stable. > >> Any chance you to check if the refactored code works with the Realtek >> device? >> I just created a "get_port_status_refactor" branch for it: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git >> get_port_status_refactor > > The hang issue is not reproduced on this kernel branch. >
Great, thanks for testing it
-Mathias
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