Re: [PATCH] mhi_bus: core: Wait for ready state after reset

From: kernel test robot
Date: Tue Feb 16 2021 - 19:40:19 EST

Hi Jeffrey,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.11 next-20210216]
[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]

url: https://github.com/0day-ci/linux/commits/Jeffrey-Hugo/mhi_bus-core-Wait-for-ready-state-after-reset/20210217-045558
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git f40ddce88593482919761f74910f42f4b84c004b
config: x86_64-randconfig-a013-20210216 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/a9148d0d4715fb099ae777ecd89a1d3fab7eb7aa
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jeffrey-Hugo/mhi_bus-core-Wait-for-ready-state-after-reset/20210217-045558
git checkout a9148d0d4715fb099ae777ecd89a1d3fab7eb7aa
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> drivers/bus/mhi/core/pm.c:501:8: warning: variable 'cur_state' is uninitialized when used here [-Wuninitialized]
cur_state == MHI_PM_SYS_ERR_PROCESS) {
^~~~~~~~~
drivers/bus/mhi/core/pm.c:451:2: note: variable 'cur_state' is declared here
enum mhi_pm_state cur_state;
^
1 warning generated.


vim +/cur_state +501 drivers/bus/mhi/core/pm.c

447
448 /* Handle shutdown transitions */
449 static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
450 {
451 enum mhi_pm_state cur_state;
452 struct mhi_event *mhi_event;
453 struct mhi_cmd_ctxt *cmd_ctxt;
454 struct mhi_cmd *mhi_cmd;
455 struct mhi_event_ctxt *er_ctxt;
456 struct device *dev = &mhi_cntrl->mhi_dev->dev;
457 int ret, i;
458
459 dev_dbg(dev, "Processing disable transition with PM state: %s\n",
460 to_mhi_pm_state_str(mhi_cntrl->pm_state));
461
462 mutex_lock(&mhi_cntrl->pm_mutex);
463
464 /* Trigger MHI RESET so that the device will not access host memory */
465 if (!MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) {
466 u32 in_reset = -1, ready = 0;
467 unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
468
469 dev_dbg(dev, "Triggering MHI Reset in device\n");
470 mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
471
472 /* Wait for the reset bit to be cleared by the device */
473 ret = wait_event_timeout(mhi_cntrl->state_event,
474 mhi_read_reg_field(mhi_cntrl,
475 mhi_cntrl->regs,
476 MHICTRL,
477 MHICTRL_RESET_MASK,
478 MHICTRL_RESET_SHIFT,
479 &in_reset) ||
480 !in_reset, timeout);
481 if (!ret || in_reset)
482 dev_err(dev, "Device failed to exit MHI Reset state\n");
483
484 /*
485 * Device will clear BHI_INTVEC as a part of RESET processing,
486 * hence re-program it
487 */
488 mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
489
490 if (!MHI_IN_PBL(mhi_get_exec_env(mhi_cntrl))) {
491 /* wait for ready to be set */
492 ret = wait_event_timeout(mhi_cntrl->state_event,
493 mhi_read_reg_field(mhi_cntrl,
494 mhi_cntrl->regs,
495 MHISTATUS,
496 MHISTATUS_READY_MASK,
497 MHISTATUS_READY_SHIFT,
498 &ready)
499 || ready, timeout);
500 if ((!ret || !ready) &&
> 501 cur_state == MHI_PM_SYS_ERR_PROCESS) {
502 dev_err(dev,
503 "Device failed to enter READY state\n");
504 mutex_unlock(&mhi_cntrl->pm_mutex);
505 return;
506 }
507 }
508 }
509
510 dev_dbg(dev,
511 "Waiting for all pending event ring processing to complete\n");
512 mhi_event = mhi_cntrl->mhi_event;
513 for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
514 if (mhi_event->offload_ev)
515 continue;
516 free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
517 tasklet_kill(&mhi_event->task);
518 }
519
520 /* Release lock and wait for all pending threads to complete */
521 mutex_unlock(&mhi_cntrl->pm_mutex);
522 dev_dbg(dev, "Waiting for all pending threads to complete\n");
523 wake_up_all(&mhi_cntrl->state_event);
524
525 dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
526 device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device);
527
528 mutex_lock(&mhi_cntrl->pm_mutex);
529
530 WARN_ON(atomic_read(&mhi_cntrl->dev_wake));
531 WARN_ON(atomic_read(&mhi_cntrl->pending_pkts));
532
533 /* Reset the ev rings and cmd rings */
534 dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n");
535 mhi_cmd = mhi_cntrl->mhi_cmd;
536 cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt;
537 for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
538 struct mhi_ring *ring = &mhi_cmd->ring;
539
540 ring->rp = ring->base;
541 ring->wp = ring->base;
542 cmd_ctxt->rp = cmd_ctxt->rbase;
543 cmd_ctxt->wp = cmd_ctxt->rbase;
544 }
545
546 mhi_event = mhi_cntrl->mhi_event;
547 er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
548 for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
549 mhi_event++) {
550 struct mhi_ring *ring = &mhi_event->ring;
551
552 /* Skip offload events */
553 if (mhi_event->offload_ev)
554 continue;
555
556 ring->rp = ring->base;
557 ring->wp = ring->base;
558 er_ctxt->rp = er_ctxt->rbase;
559 er_ctxt->wp = er_ctxt->rbase;
560 }
561
562 /* Move to disable state */
563 write_lock_irq(&mhi_cntrl->pm_lock);
564 cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
565 write_unlock_irq(&mhi_cntrl->pm_lock);
566 if (unlikely(cur_state != MHI_PM_DISABLE))
567 dev_err(dev, "Error moving from PM state: %s to: %s\n",
568 to_mhi_pm_state_str(cur_state),
569 to_mhi_pm_state_str(MHI_PM_DISABLE));
570
571 dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
572 to_mhi_pm_state_str(mhi_cntrl->pm_state),
573 TO_MHI_STATE_STR(mhi_cntrl->dev_state));
574
575 mutex_unlock(&mhi_cntrl->pm_mutex);
576 }
577

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
Description: application/gzip