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

From: Dan Carpenter
Date: Fri Feb 19 2021 - 03:38:55 EST

Hi Jeffrey,

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: i386-randconfig-m021-20210215 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

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

smatch warnings:
drivers/bus/mhi/core/pm.c:501 mhi_pm_disable_transition() error: uninitialized symbol 'cur_state'.

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

a03c7a86e12721 Bhaumik Bhatt 2020-11-09 449 static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 450 {
a03c7a86e12721 Bhaumik Bhatt 2020-11-09 451 enum mhi_pm_state cur_state;
^^^^^^^^^^^^^^^^^^^^^^^^^^^

a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 452 struct mhi_event *mhi_event;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 453 struct mhi_cmd_ctxt *cmd_ctxt;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 454 struct mhi_cmd *mhi_cmd;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 455 struct mhi_event_ctxt *er_ctxt;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 456 struct device *dev = &mhi_cntrl->mhi_dev->dev;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 457 int ret, i;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 458
a03c7a86e12721 Bhaumik Bhatt 2020-11-09 459 dev_dbg(dev, "Processing disable transition with PM state: %s\n",
a03c7a86e12721 Bhaumik Bhatt 2020-11-09 460 to_mhi_pm_state_str(mhi_cntrl->pm_state));
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 461
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 462 mutex_lock(&mhi_cntrl->pm_mutex);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 463
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 464 /* Trigger MHI RESET so that the device will not access host memory */
a03c7a86e12721 Bhaumik Bhatt 2020-11-09 465 if (!MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) {
a9148d0d4715fb Jeffrey Hugo 2021-02-16 466 u32 in_reset = -1, ready = 0;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 467 unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 468
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 469 dev_dbg(dev, "Triggering MHI Reset in device\n");
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 470 mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 471
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 472 /* Wait for the reset bit to be cleared by the device */
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 473 ret = wait_event_timeout(mhi_cntrl->state_event,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 474 mhi_read_reg_field(mhi_cntrl,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 475 mhi_cntrl->regs,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 476 MHICTRL,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 477 MHICTRL_RESET_MASK,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 478 MHICTRL_RESET_SHIFT,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 479 &in_reset) ||
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 480 !in_reset, timeout);
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 481 if (!ret || in_reset)
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 482 dev_err(dev, "Device failed to exit MHI Reset state\n");
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 483
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 484 /*
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 485 * Device will clear BHI_INTVEC as a part of RESET processing,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 486 * hence re-program it
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 487 */
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 488 mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
a9148d0d4715fb Jeffrey Hugo 2021-02-16 489
a9148d0d4715fb Jeffrey Hugo 2021-02-16 490 if (!MHI_IN_PBL(mhi_get_exec_env(mhi_cntrl))) {
a9148d0d4715fb Jeffrey Hugo 2021-02-16 491 /* wait for ready to be set */
a9148d0d4715fb Jeffrey Hugo 2021-02-16 492 ret = wait_event_timeout(mhi_cntrl->state_event,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 493 mhi_read_reg_field(mhi_cntrl,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 494 mhi_cntrl->regs,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 495 MHISTATUS,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 496 MHISTATUS_READY_MASK,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 497 MHISTATUS_READY_SHIFT,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 498 &ready)
a9148d0d4715fb Jeffrey Hugo 2021-02-16 499 || ready, timeout);
a9148d0d4715fb Jeffrey Hugo 2021-02-16 500 if ((!ret || !ready) &&
a9148d0d4715fb Jeffrey Hugo 2021-02-16 @501 cur_state == MHI_PM_SYS_ERR_PROCESS) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"cur_state" is not initialized until later.

a9148d0d4715fb Jeffrey Hugo 2021-02-16 502 dev_err(dev,
a9148d0d4715fb Jeffrey Hugo 2021-02-16 503 "Device failed to enter READY state\n");
a9148d0d4715fb Jeffrey Hugo 2021-02-16 504 mutex_unlock(&mhi_cntrl->pm_mutex);
a9148d0d4715fb Jeffrey Hugo 2021-02-16 505 return;
a9148d0d4715fb Jeffrey Hugo 2021-02-16 506 }
a9148d0d4715fb Jeffrey Hugo 2021-02-16 507 }
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 508 }
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 509
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 510 dev_dbg(dev,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 511 "Waiting for all pending event ring processing to complete\n");
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 512 mhi_event = mhi_cntrl->mhi_event;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 513 for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 514 if (mhi_event->offload_ev)
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 515 continue;
6cc1716102b554 Bhaumik Bhatt 2020-11-09 516 free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 517 tasklet_kill(&mhi_event->task);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 518 }
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 519
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 520 /* Release lock and wait for all pending threads to complete */
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 521 mutex_unlock(&mhi_cntrl->pm_mutex);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 522 dev_dbg(dev, "Waiting for all pending threads to complete\n");
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 523 wake_up_all(&mhi_cntrl->state_event);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 524
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 525 dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
10ea8bcda5ae54 Loic Poulain 2020-11-25 526 device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 527
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 528 mutex_lock(&mhi_cntrl->pm_mutex);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 529
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 530 WARN_ON(atomic_read(&mhi_cntrl->dev_wake));
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 531 WARN_ON(atomic_read(&mhi_cntrl->pending_pkts));
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 532
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 533 /* Reset the ev rings and cmd rings */
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 534 dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n");
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 535 mhi_cmd = mhi_cntrl->mhi_cmd;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 536 cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 537 for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 538 struct mhi_ring *ring = &mhi_cmd->ring;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 539
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 540 ring->rp = ring->base;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 541 ring->wp = ring->base;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 542 cmd_ctxt->rp = cmd_ctxt->rbase;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 543 cmd_ctxt->wp = cmd_ctxt->rbase;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 544 }
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 545
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 546 mhi_event = mhi_cntrl->mhi_event;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 547 er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 548 for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 549 mhi_event++) {
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 550 struct mhi_ring *ring = &mhi_event->ring;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 551
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 552 /* Skip offload events */
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 553 if (mhi_event->offload_ev)
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 554 continue;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 555
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 556 ring->rp = ring->base;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 557 ring->wp = ring->base;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 558 er_ctxt->rp = er_ctxt->rbase;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 559 er_ctxt->wp = er_ctxt->rbase;
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 560 }
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 561
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 562 /* Move to disable state */
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 563 write_lock_irq(&mhi_cntrl->pm_lock);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 564 cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 565 write_unlock_irq(&mhi_cntrl->pm_lock);
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 566 if (unlikely(cur_state != MHI_PM_DISABLE))
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 567 dev_err(dev, "Error moving from PM state: %s to: %s\n",
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 568 to_mhi_pm_state_str(cur_state),
a6e2e3522f2914 Manivannan Sadhasivam 2020-02-20 569 to_mhi_pm_state_str(MHI_PM_DISABLE));
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 570
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 571 dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 572 to_mhi_pm_state_str(mhi_cntrl->pm_state),
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 573 TO_MHI_STATE_STR(mhi_cntrl->dev_state));
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 574
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 575 mutex_unlock(&mhi_cntrl->pm_mutex);
556bbb442bbb44 Bhaumik Bhatt 2020-11-09 576 }

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

Attachment: .config.gz
Description: application/gzip