* Re: [RFT] usb: class: cdc-wdm: switch to kfifo for buffering
[not found] <20260430121859.1018894-1-oneukum@suse.com>
@ 2026-05-04 15:54 ` kernel test robot
2026-05-04 20:37 ` kernel test robot
1 sibling, 0 replies; 2+ messages in thread
From: kernel test robot @ 2026-05-04 15:54 UTC (permalink / raw)
To: Oliver Neukum, hanguidong02, linux-usb; +Cc: llvm, oe-kbuild-all, Oliver Neukum
Hi Oliver,
kernel test robot noticed the following build warnings:
[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus westeri-thunderbolt/next linus/master v7.1-rc2 next-20260430]
[cannot apply to peter-chen-usb/for-usb-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Oliver-Neukum/usb-class-cdc-wdm-switch-to-kfifo-for-buffering/20260504-164851
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link: https://lore.kernel.org/r/20260430121859.1018894-1-oneukum%40suse.com
patch subject: [RFT] usb: class: cdc-wdm: switch to kfifo for buffering
config: arm-randconfig-004-20260504 (https://download.01.org/0day-ci/archive/20260504/202605042331.sI8rgflD-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 5bac06718f502014fade905512f1d26d578a18f3)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260504/202605042331.sI8rgflD-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605042331.sI8rgflD-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/usb/class/cdc-wdm.c:526:6: warning: variable 'i' set but not used [-Wunused-but-set-variable]
526 | int i = 0;
| ^
1 warning generated.
vim +/i +526 drivers/usb/class/cdc-wdm.c
8dd5cd5395b9007 Bjørn Mork 2013-12-20 521
afba937e540c902 Oliver Neukum 2008-05-13 522 static ssize_t wdm_read
afba937e540c902 Oliver Neukum 2008-05-13 523 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
afba937e540c902 Oliver Neukum 2008-05-13 524 {
055e352971719f8 Oliver Neukum 2026-04-30 525 int rv, cntr, done;
afba937e540c902 Oliver Neukum 2008-05-13 @526 int i = 0;
afba937e540c902 Oliver Neukum 2008-05-13 527 struct wdm_device *desc = file->private_data;
afba937e540c902 Oliver Neukum 2008-05-13 528
afba937e540c902 Oliver Neukum 2008-05-13 529
e8537bd2c4f325a Bjørn Mork 2012-01-16 530 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
afba937e540c902 Oliver Neukum 2008-05-13 531 if (rv < 0)
afba937e540c902 Oliver Neukum 2008-05-13 532 return -ERESTARTSYS;
afba937e540c902 Oliver Neukum 2008-05-13 533
055e352971719f8 Oliver Neukum 2026-04-30 534 cntr = kfifo_len(&desc->ubuf);
711c68b3c0f7a92 Ben Hutchings 2012-02-12 535 if (cntr == 0) {
afba937e540c902 Oliver Neukum 2008-05-13 536 desc->read = 0;
afba937e540c902 Oliver Neukum 2008-05-13 537 retry:
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 538 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 539 rv = -ENODEV;
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 540 goto err;
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 541 }
c0f5ecee4e74166 Oliver Neukum 2013-03-12 542 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
c0f5ecee4e74166 Oliver Neukum 2013-03-12 543 clear_bit(WDM_OVERFLOW, &desc->flags);
c0f5ecee4e74166 Oliver Neukum 2013-03-12 544 rv = -ENOBUFS;
c0f5ecee4e74166 Oliver Neukum 2013-03-12 545 goto err;
c0f5ecee4e74166 Oliver Neukum 2013-03-12 546 }
afba937e540c902 Oliver Neukum 2008-05-13 547 i++;
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 548 if (file->f_flags & O_NONBLOCK) {
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 549 if (!test_bit(WDM_READ, &desc->flags)) {
53b7f7b53d83727 Gustavo A. R. Silva 2017-02-14 550 rv = -EAGAIN;
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 551 goto err;
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 552 }
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 553 rv = 0;
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 554 } else {
afba937e540c902 Oliver Neukum 2008-05-13 555 rv = wait_event_interruptible(desc->wait,
afba937e540c902 Oliver Neukum 2008-05-13 556 test_bit(WDM_READ, &desc->flags));
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 557 }
afba937e540c902 Oliver Neukum 2008-05-13 558
7f1dc313d01f5f0 Oliver Neukum 2009-09-09 559 /* may have happened while we slept */
17d80d562fd78a0 Oliver Neukum 2008-06-24 560 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
17d80d562fd78a0 Oliver Neukum 2008-06-24 561 rv = -ENODEV;
17d80d562fd78a0 Oliver Neukum 2008-06-24 562 goto err;
17d80d562fd78a0 Oliver Neukum 2008-06-24 563 }
88044202756925a Bjørn Mork 2012-02-10 564 if (test_bit(WDM_RESETTING, &desc->flags)) {
88044202756925a Bjørn Mork 2012-02-10 565 rv = -EIO;
88044202756925a Bjørn Mork 2012-02-10 566 goto err;
88044202756925a Bjørn Mork 2012-02-10 567 }
055e352971719f8 Oliver Neukum 2026-04-30 568 smp_rmb(); /* against wdm_in_callback() */
055e352971719f8 Oliver Neukum 2026-04-30 569 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
055e352971719f8 Oliver Neukum 2026-04-30 570 clear_bit(WDM_OVERFLOW, &desc->flags);
055e352971719f8 Oliver Neukum 2026-04-30 571 rv = -ENOBUFS;
055e352971719f8 Oliver Neukum 2026-04-30 572 goto err;
055e352971719f8 Oliver Neukum 2026-04-30 573 }
055e352971719f8 Oliver Neukum 2026-04-30 574
17d80d562fd78a0 Oliver Neukum 2008-06-24 575 usb_mark_last_busy(interface_to_usbdev(desc->intf));
afba937e540c902 Oliver Neukum 2008-05-13 576 if (rv < 0) {
afba937e540c902 Oliver Neukum 2008-05-13 577 rv = -ERESTARTSYS;
afba937e540c902 Oliver Neukum 2008-05-13 578 goto err;
afba937e540c902 Oliver Neukum 2008-05-13 579 }
afba937e540c902 Oliver Neukum 2008-05-13 580
afba937e540c902 Oliver Neukum 2008-05-13 581 spin_lock_irq(&desc->iuspin);
afba937e540c902 Oliver Neukum 2008-05-13 582
afba937e540c902 Oliver Neukum 2008-05-13 583 if (desc->rerr) { /* read completed, error happened */
85e8a0b9a3565c8 Oliver Neukum 2015-03-23 584 rv = usb_translate_errors(desc->rerr);
afba937e540c902 Oliver Neukum 2008-05-13 585 desc->rerr = 0;
afba937e540c902 Oliver Neukum 2008-05-13 586 spin_unlock_irq(&desc->iuspin);
afba937e540c902 Oliver Neukum 2008-05-13 587 goto err;
afba937e540c902 Oliver Neukum 2008-05-13 588 }
afba937e540c902 Oliver Neukum 2008-05-13 589 /*
afba937e540c902 Oliver Neukum 2008-05-13 590 * recheck whether we've lost the race
afba937e540c902 Oliver Neukum 2008-05-13 591 * against the completion handler
afba937e540c902 Oliver Neukum 2008-05-13 592 */
afba937e540c902 Oliver Neukum 2008-05-13 593 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
afba937e540c902 Oliver Neukum 2008-05-13 594 spin_unlock_irq(&desc->iuspin);
afba937e540c902 Oliver Neukum 2008-05-13 595 goto retry;
afba937e540c902 Oliver Neukum 2008-05-13 596 }
c0f5ecee4e74166 Oliver Neukum 2013-03-12 597
055e352971719f8 Oliver Neukum 2026-04-30 598 cntr = kfifo_len(&desc->ubuf);
afba937e540c902 Oliver Neukum 2008-05-13 599 spin_unlock_irq(&desc->iuspin);
afba937e540c902 Oliver Neukum 2008-05-13 600 }
afba937e540c902 Oliver Neukum 2008-05-13 601
711c68b3c0f7a92 Ben Hutchings 2012-02-12 602 if (cntr > count)
711c68b3c0f7a92 Ben Hutchings 2012-02-12 603 cntr = count;
055e352971719f8 Oliver Neukum 2026-04-30 604 rv = kfifo_to_user(&desc->ubuf, buffer, cntr, &done);
055e352971719f8 Oliver Neukum 2026-04-30 605 if (rv < 0) {
afba937e540c902 Oliver Neukum 2008-05-13 606 rv = -EFAULT;
afba937e540c902 Oliver Neukum 2008-05-13 607 goto err;
afba937e540c902 Oliver Neukum 2008-05-13 608 }
afba937e540c902 Oliver Neukum 2008-05-13 609
711c68b3c0f7a92 Ben Hutchings 2012-02-12 610 spin_lock_irq(&desc->iuspin);
711c68b3c0f7a92 Ben Hutchings 2012-02-12 611
87d65e54b6d5ff6 Oliver Neukum 2008-06-19 612 /* in case we had outstanding data */
055e352971719f8 Oliver Neukum 2026-04-30 613 if (kfifo_is_empty(&desc->ubuf)) {
c1da59dad0ebd3f Robert Foss 2016-08-09 614 clear_bit(WDM_READ, &desc->flags);
c1da59dad0ebd3f Robert Foss 2016-08-09 615 service_outstanding_interrupt(desc);
c1da59dad0ebd3f Robert Foss 2016-08-09 616 }
73e06865ead1bec Greg Suarez 2013-10-29 617 spin_unlock_irq(&desc->iuspin);
055e352971719f8 Oliver Neukum 2026-04-30 618 rv = done;
afba937e540c902 Oliver Neukum 2008-05-13 619
afba937e540c902 Oliver Neukum 2008-05-13 620 err:
e8537bd2c4f325a Bjørn Mork 2012-01-16 621 mutex_unlock(&desc->rlock);
afba937e540c902 Oliver Neukum 2008-05-13 622 return rv;
afba937e540c902 Oliver Neukum 2008-05-13 623 }
afba937e540c902 Oliver Neukum 2008-05-13 624
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [RFT] usb: class: cdc-wdm: switch to kfifo for buffering
[not found] <20260430121859.1018894-1-oneukum@suse.com>
2026-05-04 15:54 ` [RFT] usb: class: cdc-wdm: switch to kfifo for buffering kernel test robot
@ 2026-05-04 20:37 ` kernel test robot
1 sibling, 0 replies; 2+ messages in thread
From: kernel test robot @ 2026-05-04 20:37 UTC (permalink / raw)
To: Oliver Neukum, hanguidong02, linux-usb; +Cc: llvm, oe-kbuild-all, Oliver Neukum
Hi Oliver,
kernel test robot noticed the following build warnings:
[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus westeri-thunderbolt/next next-20260430]
[cannot apply to peter-chen-usb/for-usb-next linus/master v6.16-rc1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Oliver-Neukum/usb-class-cdc-wdm-switch-to-kfifo-for-buffering/20260504-164851
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link: https://lore.kernel.org/r/20260430121859.1018894-1-oneukum%40suse.com
patch subject: [RFT] usb: class: cdc-wdm: switch to kfifo for buffering
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20260504/202605042206.Ybpa1c91-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260504/202605042206.Ybpa1c91-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605042206.Ybpa1c91-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/usb/class/cdc-wdm.c:526:6: warning: variable 'i' set but not used [-Wunused-but-set-variable]
526 | int i = 0;
| ^
1 warning generated.
vim +/i +526 drivers/usb/class/cdc-wdm.c
8dd5cd5395b900 Bjørn Mork 2013-12-20 521
afba937e540c90 Oliver Neukum 2008-05-13 522 static ssize_t wdm_read
afba937e540c90 Oliver Neukum 2008-05-13 523 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
afba937e540c90 Oliver Neukum 2008-05-13 524 {
055e352971719f Oliver Neukum 2026-04-30 525 int rv, cntr, done;
afba937e540c90 Oliver Neukum 2008-05-13 @526 int i = 0;
afba937e540c90 Oliver Neukum 2008-05-13 527 struct wdm_device *desc = file->private_data;
afba937e540c90 Oliver Neukum 2008-05-13 528
afba937e540c90 Oliver Neukum 2008-05-13 529
e8537bd2c4f325 Bjørn Mork 2012-01-16 530 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
afba937e540c90 Oliver Neukum 2008-05-13 531 if (rv < 0)
afba937e540c90 Oliver Neukum 2008-05-13 532 return -ERESTARTSYS;
afba937e540c90 Oliver Neukum 2008-05-13 533
055e352971719f Oliver Neukum 2026-04-30 534 cntr = kfifo_len(&desc->ubuf);
711c68b3c0f7a9 Ben Hutchings 2012-02-12 535 if (cntr == 0) {
afba937e540c90 Oliver Neukum 2008-05-13 536 desc->read = 0;
afba937e540c90 Oliver Neukum 2008-05-13 537 retry:
7f1dc313d01f5f Oliver Neukum 2009-09-09 538 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
7f1dc313d01f5f Oliver Neukum 2009-09-09 539 rv = -ENODEV;
7f1dc313d01f5f Oliver Neukum 2009-09-09 540 goto err;
7f1dc313d01f5f Oliver Neukum 2009-09-09 541 }
c0f5ecee4e7416 Oliver Neukum 2013-03-12 542 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
c0f5ecee4e7416 Oliver Neukum 2013-03-12 543 clear_bit(WDM_OVERFLOW, &desc->flags);
c0f5ecee4e7416 Oliver Neukum 2013-03-12 544 rv = -ENOBUFS;
c0f5ecee4e7416 Oliver Neukum 2013-03-12 545 goto err;
c0f5ecee4e7416 Oliver Neukum 2013-03-12 546 }
afba937e540c90 Oliver Neukum 2008-05-13 547 i++;
7f1dc313d01f5f Oliver Neukum 2009-09-09 548 if (file->f_flags & O_NONBLOCK) {
7f1dc313d01f5f Oliver Neukum 2009-09-09 549 if (!test_bit(WDM_READ, &desc->flags)) {
53b7f7b53d8372 Gustavo A. R. Silva 2017-02-14 550 rv = -EAGAIN;
7f1dc313d01f5f Oliver Neukum 2009-09-09 551 goto err;
7f1dc313d01f5f Oliver Neukum 2009-09-09 552 }
7f1dc313d01f5f Oliver Neukum 2009-09-09 553 rv = 0;
7f1dc313d01f5f Oliver Neukum 2009-09-09 554 } else {
afba937e540c90 Oliver Neukum 2008-05-13 555 rv = wait_event_interruptible(desc->wait,
afba937e540c90 Oliver Neukum 2008-05-13 556 test_bit(WDM_READ, &desc->flags));
7f1dc313d01f5f Oliver Neukum 2009-09-09 557 }
afba937e540c90 Oliver Neukum 2008-05-13 558
7f1dc313d01f5f Oliver Neukum 2009-09-09 559 /* may have happened while we slept */
17d80d562fd78a Oliver Neukum 2008-06-24 560 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
17d80d562fd78a Oliver Neukum 2008-06-24 561 rv = -ENODEV;
17d80d562fd78a Oliver Neukum 2008-06-24 562 goto err;
17d80d562fd78a Oliver Neukum 2008-06-24 563 }
88044202756925 Bjørn Mork 2012-02-10 564 if (test_bit(WDM_RESETTING, &desc->flags)) {
88044202756925 Bjørn Mork 2012-02-10 565 rv = -EIO;
88044202756925 Bjørn Mork 2012-02-10 566 goto err;
88044202756925 Bjørn Mork 2012-02-10 567 }
055e352971719f Oliver Neukum 2026-04-30 568 smp_rmb(); /* against wdm_in_callback() */
055e352971719f Oliver Neukum 2026-04-30 569 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
055e352971719f Oliver Neukum 2026-04-30 570 clear_bit(WDM_OVERFLOW, &desc->flags);
055e352971719f Oliver Neukum 2026-04-30 571 rv = -ENOBUFS;
055e352971719f Oliver Neukum 2026-04-30 572 goto err;
055e352971719f Oliver Neukum 2026-04-30 573 }
055e352971719f Oliver Neukum 2026-04-30 574
17d80d562fd78a Oliver Neukum 2008-06-24 575 usb_mark_last_busy(interface_to_usbdev(desc->intf));
afba937e540c90 Oliver Neukum 2008-05-13 576 if (rv < 0) {
afba937e540c90 Oliver Neukum 2008-05-13 577 rv = -ERESTARTSYS;
afba937e540c90 Oliver Neukum 2008-05-13 578 goto err;
afba937e540c90 Oliver Neukum 2008-05-13 579 }
afba937e540c90 Oliver Neukum 2008-05-13 580
afba937e540c90 Oliver Neukum 2008-05-13 581 spin_lock_irq(&desc->iuspin);
afba937e540c90 Oliver Neukum 2008-05-13 582
afba937e540c90 Oliver Neukum 2008-05-13 583 if (desc->rerr) { /* read completed, error happened */
85e8a0b9a3565c Oliver Neukum 2015-03-23 584 rv = usb_translate_errors(desc->rerr);
afba937e540c90 Oliver Neukum 2008-05-13 585 desc->rerr = 0;
afba937e540c90 Oliver Neukum 2008-05-13 586 spin_unlock_irq(&desc->iuspin);
afba937e540c90 Oliver Neukum 2008-05-13 587 goto err;
afba937e540c90 Oliver Neukum 2008-05-13 588 }
afba937e540c90 Oliver Neukum 2008-05-13 589 /*
afba937e540c90 Oliver Neukum 2008-05-13 590 * recheck whether we've lost the race
afba937e540c90 Oliver Neukum 2008-05-13 591 * against the completion handler
afba937e540c90 Oliver Neukum 2008-05-13 592 */
afba937e540c90 Oliver Neukum 2008-05-13 593 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
afba937e540c90 Oliver Neukum 2008-05-13 594 spin_unlock_irq(&desc->iuspin);
afba937e540c90 Oliver Neukum 2008-05-13 595 goto retry;
afba937e540c90 Oliver Neukum 2008-05-13 596 }
c0f5ecee4e7416 Oliver Neukum 2013-03-12 597
055e352971719f Oliver Neukum 2026-04-30 598 cntr = kfifo_len(&desc->ubuf);
afba937e540c90 Oliver Neukum 2008-05-13 599 spin_unlock_irq(&desc->iuspin);
afba937e540c90 Oliver Neukum 2008-05-13 600 }
afba937e540c90 Oliver Neukum 2008-05-13 601
711c68b3c0f7a9 Ben Hutchings 2012-02-12 602 if (cntr > count)
711c68b3c0f7a9 Ben Hutchings 2012-02-12 603 cntr = count;
055e352971719f Oliver Neukum 2026-04-30 604 rv = kfifo_to_user(&desc->ubuf, buffer, cntr, &done);
055e352971719f Oliver Neukum 2026-04-30 605 if (rv < 0) {
afba937e540c90 Oliver Neukum 2008-05-13 606 rv = -EFAULT;
afba937e540c90 Oliver Neukum 2008-05-13 607 goto err;
afba937e540c90 Oliver Neukum 2008-05-13 608 }
afba937e540c90 Oliver Neukum 2008-05-13 609
711c68b3c0f7a9 Ben Hutchings 2012-02-12 610 spin_lock_irq(&desc->iuspin);
711c68b3c0f7a9 Ben Hutchings 2012-02-12 611
87d65e54b6d5ff Oliver Neukum 2008-06-19 612 /* in case we had outstanding data */
055e352971719f Oliver Neukum 2026-04-30 613 if (kfifo_is_empty(&desc->ubuf)) {
c1da59dad0ebd3 Robert Foss 2016-08-09 614 clear_bit(WDM_READ, &desc->flags);
c1da59dad0ebd3 Robert Foss 2016-08-09 615 service_outstanding_interrupt(desc);
c1da59dad0ebd3 Robert Foss 2016-08-09 616 }
73e06865ead1be Greg Suarez 2013-10-29 617 spin_unlock_irq(&desc->iuspin);
055e352971719f Oliver Neukum 2026-04-30 618 rv = done;
afba937e540c90 Oliver Neukum 2008-05-13 619
afba937e540c90 Oliver Neukum 2008-05-13 620 err:
e8537bd2c4f325 Bjørn Mork 2012-01-16 621 mutex_unlock(&desc->rlock);
afba937e540c90 Oliver Neukum 2008-05-13 622 return rv;
afba937e540c90 Oliver Neukum 2008-05-13 623 }
afba937e540c90 Oliver Neukum 2008-05-13 624
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 2+ messages in thread