lkml.org 
[lkml]   [2022]   [Jun]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 019/667] usb: core: hcd: Add support for deferring roothub registration
    Date
    From: Kishon Vijay Abraham I <kishon@ti.com>

    commit a44623d9279086c89f631201d993aa332f7c9e66 upstream.

    It has been observed with certain PCIe USB cards (like Inateck connected
    to AM64 EVM or J7200 EVM) that as soon as the primary roothub is
    registered, port status change is handled even before xHC is running
    leading to cold plug USB devices not detected. For such cases, registering
    both the root hubs along with the second HCD is required. Add support for
    deferring roothub registration in usb_add_hcd(), so that both primary and
    secondary roothubs are registered along with the second HCD.

    This patch has been added and reverted earier as it triggered a race
    in usb device enumeration.
    That race is now fixed in 5.16-rc3, and in stable back to 5.4
    commit 6cca13de26ee ("usb: hub: Fix locking issues with address0_mutex")
    commit 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0
    race")

    CC: stable@vger.kernel.org # 5.4+
    Suggested-by: Mathias Nyman <mathias.nyman@linux.intel.com>
    Tested-by: Chris Chiu <chris.chiu@canonical.com>
    Acked-by: Alan Stern <stern@rowland.harvard.edu>
    Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
    Link: https://lore.kernel.org/r/20220510091630.16564-2-kishon@ti.com
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    drivers/usb/core/hcd.c | 29 +++++++++++++++++++++++------
    include/linux/usb/hcd.h | 2 ++
    2 files changed, 25 insertions(+), 6 deletions(-)

    --- a/drivers/usb/core/hcd.c
    +++ b/drivers/usb/core/hcd.c
    @@ -2816,6 +2816,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
    {
    int retval;
    struct usb_device *rhdev;
    + struct usb_hcd *shared_hcd;

    if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
    hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
    @@ -2976,13 +2977,26 @@ int usb_add_hcd(struct usb_hcd *hcd,
    goto err_hcd_driver_start;
    }

    + /* starting here, usbcore will pay attention to the shared HCD roothub */
    + shared_hcd = hcd->shared_hcd;
    + if (!usb_hcd_is_primary_hcd(hcd) && shared_hcd && HCD_DEFER_RH_REGISTER(shared_hcd)) {
    + retval = register_root_hub(shared_hcd);
    + if (retval != 0)
    + goto err_register_root_hub;
    +
    + if (shared_hcd->uses_new_polling && HCD_POLL_RH(shared_hcd))
    + usb_hcd_poll_rh_status(shared_hcd);
    + }
    +
    /* starting here, usbcore will pay attention to this root hub */
    - retval = register_root_hub(hcd);
    - if (retval != 0)
    - goto err_register_root_hub;
    + if (!HCD_DEFER_RH_REGISTER(hcd)) {
    + retval = register_root_hub(hcd);
    + if (retval != 0)
    + goto err_register_root_hub;

    - if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
    - usb_hcd_poll_rh_status(hcd);
    + if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
    + usb_hcd_poll_rh_status(hcd);
    + }

    return retval;

    @@ -3020,6 +3034,7 @@ EXPORT_SYMBOL_GPL(usb_add_hcd);
    void usb_remove_hcd(struct usb_hcd *hcd)
    {
    struct usb_device *rhdev = hcd->self.root_hub;
    + bool rh_registered;

    dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);

    @@ -3030,6 +3045,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)

    dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
    spin_lock_irq (&hcd_root_hub_lock);
    + rh_registered = hcd->rh_registered;
    hcd->rh_registered = 0;
    spin_unlock_irq (&hcd_root_hub_lock);

    @@ -3039,7 +3055,8 @@ void usb_remove_hcd(struct usb_hcd *hcd)
    cancel_work_sync(&hcd->died_work);

    mutex_lock(&usb_bus_idr_lock);
    - usb_disconnect(&rhdev); /* Sets rhdev to NULL */
    + if (rh_registered)
    + usb_disconnect(&rhdev); /* Sets rhdev to NULL */
    mutex_unlock(&usb_bus_idr_lock);

    /*
    --- a/include/linux/usb/hcd.h
    +++ b/include/linux/usb/hcd.h
    @@ -124,6 +124,7 @@ struct usb_hcd {
    #define HCD_FLAG_RH_RUNNING 5 /* root hub is running? */
    #define HCD_FLAG_DEAD 6 /* controller has died? */
    #define HCD_FLAG_INTF_AUTHORIZED 7 /* authorize interfaces? */
    +#define HCD_FLAG_DEFER_RH_REGISTER 8 /* Defer roothub registration */

    /* The flags can be tested using these macros; they are likely to
    * be slightly faster than test_bit().
    @@ -134,6 +135,7 @@ struct usb_hcd {
    #define HCD_WAKEUP_PENDING(hcd) ((hcd)->flags & (1U << HCD_FLAG_WAKEUP_PENDING))
    #define HCD_RH_RUNNING(hcd) ((hcd)->flags & (1U << HCD_FLAG_RH_RUNNING))
    #define HCD_DEAD(hcd) ((hcd)->flags & (1U << HCD_FLAG_DEAD))
    +#define HCD_DEFER_RH_REGISTER(hcd) ((hcd)->flags & (1U << HCD_FLAG_DEFER_RH_REGISTER))

    /*
    * Specifies if interfaces are authorized by default

    \
     
     \ /
      Last update: 2022-06-07 20:19    [W:2.435 / U:1.296 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site