lkml.org 
[lkml]   [2014]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.13 058/163] xhci: fix oops when xhci resumes from hibernate with hw lpm capable devices
    Date
    3.13.11.9 -stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Mathias Nyman <mathias.nyman@linux.intel.com>

    commit 96044694b8511bc2b04df0776b4ba295cfe005c0 upstream.

    Resuming from hibernate (S4) will restart and re-initialize xHC.
    The device contexts are freed and will be re-allocated later during device reset.

    Usb core will disable link pm in device resume before device reset, which will
    try to change the max exit latency, accessing the device contexts before they are re-allocated.

    There is no need to zero (disable) the max exit latency when disabling hw lpm
    for a freshly re-initialized xHC. So check that device context exists before
    doing anything. The max exit latency will be set again after device reset when usb core
    enables the link pm.

    Reported-by: Imre Deak <imre.deak@intel.com>
    Tested-by: Imre Deak <imre.deak@intel.com>
    Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Kamal Mostafa <kamal@canonical.com>
    ---
    drivers/usb/host/xhci.c | 12 ++++++++++--
    1 file changed, 10 insertions(+), 2 deletions(-)

    diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
    index a879287..959e769 100644
    --- a/drivers/usb/host/xhci.c
    +++ b/drivers/usb/host/xhci.c
    @@ -3917,13 +3917,21 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
    int ret;

    spin_lock_irqsave(&xhci->lock, flags);
    - if (max_exit_latency == xhci->devs[udev->slot_id]->current_mel) {
    +
    + virt_dev = xhci->devs[udev->slot_id];
    +
    + /*
    + * virt_dev might not exists yet if xHC resumed from hibernate (S4) and
    + * xHC was re-initialized. Exit latency will be set later after
    + * hub_port_finish_reset() is done and xhci->devs[] are re-allocated
    + */
    +
    + if (!virt_dev || max_exit_latency == virt_dev->current_mel) {
    spin_unlock_irqrestore(&xhci->lock, flags);
    return 0;
    }

    /* Attempt to issue an Evaluate Context command to change the MEL. */
    - virt_dev = xhci->devs[udev->slot_id];
    command = xhci->lpm_command;
    ctrl_ctx = xhci_get_input_control_ctx(xhci, command->in_ctx);
    if (!ctrl_ctx) {
    --
    1.9.1


    \
     
     \ /
      Last update: 2014-10-09 23:41    [W:5.772 / U:0.228 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site