Thanks Den Carpenter for information. yes, i will modify new patch version accordingly to add for mutex_unlock(hcd->bandwidth_mutex); before returning. >Hi Aman, > >kernel test robot noticed the following build warnings: > >https://git-scm.com/docs/git-format-patch#_base_tree_information] > >url: https://protect2.fireeye.com/v1/url?k=c33c7aba-a2b76f89-c33df1f5-000babff9bb7-672d2cfefe2327a5&q=1&e=0dbea670-3cf3-4a45-a999->157e4e0dcad9&u=https%3A%2F%2Fgithub.com%2Fintel-lab-lkp%2Flinux%2Fcommits%2FAman-Deep%2FUSB-Fix-race-condition-during-UVC-webcam-disconnect%2F20230720->202046 >base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing >patch link: https://lore.kernel.org/r/20230720113142.3070583-1-aman.deep%40samsung.com >patch subject: [PATCH] USB: Fix race condition during UVC webcam disconnect >config: parisc-randconfig-m041-20230726 (https://download.01.org/0day-ci/archive/20230727/202307270834.rpaexQSs-lkp@xxxxxxxxx/config) >compiler: hppa-linux-gcc (GCC) 12.3.0 >reproduce: (https://download.01.org/0day-ci/archive/20230727/202307270834.rpaexQSs-lkp@xxxxxxxxx/reproduce) > >If you fix the issue in a separate patch/commit (i.e. not just a new version of >the same patch/commit), kindly add following tags >| Reported-by: kernel test robot <lkp@xxxxxxxxx> >| Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> >| Closes: https://lore.kernel.org/r/202307270834.rpaexQSs-lkp@xxxxxxxxx/ we will add it when creating new patch version. > >smatch warnings: >drivers/usb/core/message.c:1668 usb_set_interface() warn: inconsistent returns 'hcd->bandwidth_mutex'. > >vim +1668 drivers/usb/core/message.c > >^1da177e4c3f41 Linus Torvalds 2005-04-16 1528 int usb_set_interface(struct usb_device *dev, int interface, int alternate) >^1da177e4c3f41 Linus Torvalds 2005-04-16 1529 { >^1da177e4c3f41 Linus Torvalds 2005-04-16 1530 struct usb_interface *iface; >^1da177e4c3f41 Linus Torvalds 2005-04-16 1531 struct usb_host_interface *alt; >3f0479e00a3fca Sarah Sharp 2009-12-03 1532 struct usb_hcd *hcd = bus_to_hcd(dev->bus); >7a7b562d08ad6d Hans de Goede 2013-11-08 1533 int i, ret, manual = 0; >3e35bf39e0b909 Greg Kroah-Hartman 2008-01-30 1534 unsigned int epaddr; >3e35bf39e0b909 Greg Kroah-Hartman 2008-01-30 1535 unsigned int pipe; >^1da177e4c3f41 Linus Torvalds 2005-04-16 1536 >^1da177e4c3f41 Linus Torvalds 2005-04-16 1537 if (dev->state == USB_STATE_SUSPENDED) >^1da177e4c3f41 Linus Torvalds 2005-04-16 1538 return -EHOSTUNREACH; >^1da177e4c3f41 Linus Torvalds 2005-04-16 1539 >^1da177e4c3f41 Linus Torvalds 2005-04-16 1540 iface = usb_ifnum_to_if(dev, interface); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1541 if (!iface) { >^1da177e4c3f41 Linus Torvalds 2005-04-16 1542 dev_dbg(&dev->dev, "selecting invalid interface %d\n", >^1da177e4c3f41 Linus Torvalds 2005-04-16 1543 interface); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1544 return -EINVAL; >^1da177e4c3f41 Linus Torvalds 2005-04-16 1545 } >e534c5b831c8b8 Alan Stern 2011-07-01 1546 if (iface->unregistering) >e534c5b831c8b8 Alan Stern 2011-07-01 1547 return -ENODEV; >^1da177e4c3f41 Linus Torvalds 2005-04-16 1548 >^1da177e4c3f41 Linus Torvalds 2005-04-16 1549 alt = usb_altnum_to_altsetting(iface, alternate); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1550 if (!alt) { >385f690bc058ba Thadeu Lima de Souza Cascardo 2010-01-17 1551 dev_warn(&dev->dev, "selecting invalid altsetting %d\n", >3b6004f3b5a8b4 Greg Kroah-Hartman 2008-08-14 1552 alternate); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1553 return -EINVAL; >^1da177e4c3f41 Linus Torvalds 2005-04-16 1554 } >f9a5b4f58b280c Mathias Nyman 2018-09-03 1555 /* >f9a5b4f58b280c Mathias Nyman 2018-09-03 1556 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth, >f9a5b4f58b280c Mathias Nyman 2018-09-03 1557 * including freeing dropped endpoint ring buffers. >f9a5b4f58b280c Mathias Nyman 2018-09-03 1558 * Make sure the interface endpoints are flushed before that >f9a5b4f58b280c Mathias Nyman 2018-09-03 1559 */ >f9a5b4f58b280c Mathias Nyman 2018-09-03 1560 usb_disable_interface(dev, iface, false); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1561 >3f0479e00a3fca Sarah Sharp 2009-12-03 1562 /* Make sure we have enough bandwidth for this alternate interface. >3f0479e00a3fca Sarah Sharp 2009-12-03 1563 * Remove the current alt setting and add the new alt setting. >3f0479e00a3fca Sarah Sharp 2009-12-03 1564 */ >d673bfcbfffdeb Sarah Sharp 2010-10-15 1565 mutex_lock(hcd->bandwidth_mutex); >8306095fd2c110 Sarah Sharp 2012-05-02 1566 /* Disable LPM, and re-enable it once the new alt setting is installed, >8306095fd2c110 Sarah Sharp 2012-05-02 1567 * so that the xHCI driver can recalculate the U1/U2 timeouts. >8306095fd2c110 Sarah Sharp 2012-05-02 1568 */ >8306095fd2c110 Sarah Sharp 2012-05-02 1569 if (usb_disable_lpm(dev)) { >1ccc417e6c3201 Joe Perches 2017-12-05 1570 dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__); >8306095fd2c110 Sarah Sharp 2012-05-02 1571 mutex_unlock(hcd->bandwidth_mutex); >8306095fd2c110 Sarah Sharp 2012-05-02 1572 return -ENOMEM; >8306095fd2c110 Sarah Sharp 2012-05-02 1573 } >7a7b562d08ad6d Hans de Goede 2013-11-08 1574 /* Changing alt-setting also frees any allocated streams */ >7a7b562d08ad6d Hans de Goede 2013-11-08 1575 for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++) >7a7b562d08ad6d Hans de Goede 2013-11-08 1576 iface->cur_altsetting->endpoint[i].streams = 0; >7a7b562d08ad6d Hans de Goede 2013-11-08 1577 >4682bbb9e2f196 Aman Deep 2023-07-20 1578 if (dev->state == USB_STATE_NOTATTACHED) >4682bbb9e2f196 Aman Deep 2023-07-20 1579 return -ENODEV; > > >mutex_unlock(hcd->bandwidth_mutex); before returning > >4682bbb9e2f196 Aman Deep 2023-07-20 1580 >3f0479e00a3fca Sarah Sharp 2009-12-03 1581 ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt); >4682bbb9e2f196 Aman Deep 2023-07-20 1582 >3f0479e00a3fca Sarah Sharp 2009-12-03 1583 if (ret < 0) { >3f0479e00a3fca Sarah Sharp 2009-12-03 1584 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n", >3f0479e00a3fca Sarah Sharp 2009-12-03 1585 alternate); >8306095fd2c110 Sarah Sharp 2012-05-02 1586 usb_enable_lpm(dev); >d673bfcbfffdeb Sarah Sharp 2010-10-15 1587 mutex_unlock(hcd->bandwidth_mutex); >3f0479e00a3fca Sarah Sharp 2009-12-03 1588 return ret; >3f0479e00a3fca Sarah Sharp 2009-12-03 1589 } >3f0479e00a3fca Sarah Sharp 2009-12-03 1590 >392e1d9817d002 Alan Stern 2008-03-11 1591 if (dev->quirks & USB_QUIRK_NO_SET_INTF) >392e1d9817d002 Alan Stern 2008-03-11 1592 ret = -EPIPE; >392e1d9817d002 Alan Stern 2008-03-11 1593 else >297e84c04d76b9 Greg Kroah-Hartman 2020-09-14 1594 ret = usb_control_msg_send(dev, 0, >297e84c04d76b9 Greg Kroah-Hartman 2020-09-14 1595 USB_REQ_SET_INTERFACE, >297e84c04d76b9 Greg Kroah-Hartman 2020-09-14 1596 USB_RECIP_INTERFACE, alternate, >ddd1198e3e0935 Oliver Neukum 2020-09-23 1597 interface, NULL, 0, 5000, >ddd1198e3e0935 Oliver Neukum 2020-09-23 1598 GFP_NOIO); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1599 >^1da177e4c3f41 Linus Torvalds 2005-04-16 1600 /* 9.4.10 says devices don't need this and are free to STALL the >^1da177e4c3f41 Linus Torvalds 2005-04-16 1601 * request if the interface only has one alternate setting. >^1da177e4c3f41 Linus Torvalds 2005-04-16 1602 */ >^1da177e4c3f41 Linus Torvalds 2005-04-16 1603 if (ret == -EPIPE && iface->num_altsetting == 1) { >^1da177e4c3f41 Linus Torvalds 2005-04-16 1604 dev_dbg(&dev->dev, >^1da177e4c3f41 Linus Torvalds 2005-04-16 1605 "manual set_interface for iface %d, alt %d\n", >^1da177e4c3f41 Linus Torvalds 2005-04-16 1606 interface, alternate); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1607 manual = 1; >297e84c04d76b9 Greg Kroah-Hartman 2020-09-14 1608 } else if (ret) { >3f0479e00a3fca Sarah Sharp 2009-12-03 1609 /* Re-instate the old alt setting */ >3f0479e00a3fca Sarah Sharp 2009-12-03 1610 usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting); >8306095fd2c110 Sarah Sharp 2012-05-02 1611 usb_enable_lpm(dev); >d673bfcbfffdeb Sarah Sharp 2010-10-15 1612 mutex_unlock(hcd->bandwidth_mutex); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1613 return ret; >3f0479e00a3fca Sarah Sharp 2009-12-03 1614 } >d673bfcbfffdeb Sarah Sharp 2010-10-15 1615 mutex_unlock(hcd->bandwidth_mutex); >^1da177e4c3f41 Linus Torvalds 2005-04-16 1616 >^1da177e4c3f41 Linus Torvalds 2005-04-16 1617 /* FIXME drivers shouldn't need to replicate/bugfix the logic here >^1da177e4c3f41 Linus Torvalds 2005-04-16 1618 * when they implement async or easily-killable versions of this or >^1da177e4c3f41 Linus Torvalds 2005-04-16 1619 * other "should-be-internal" functions (like clear_halt). >^1da177e4c3f41 Linus Torvalds 2005-04-16 1620 * should hcd+usbcore postprocess control requests? > >-- >0-DAY CI Kernel Test Service >https://protect2.fireeye.com/v1/url?k=f58bda35-9400cf06-f58a517a-000babff9bb7-d72ab9bab3df6b4a&q=1&e=0dbea670-3cf3-4a45-a999->157e4e0dcad9&u=https%3A%2F%2Fgithub.com%2Fintel%2Flkp-tests%2Fwiki > > Thanks, Aman
