Hi Aman, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Aman-Deep/USB-Fix-race-condition-during-UVC-webcam-disconnect/20230720-202046 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/ 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://github.com/intel/lkp-tests/wiki
