Reading TMC mode register without proper coresight power management can lead to exceptions like the one in the call trace below in tmc_read_unprepare_etb() when the trace data is read after the sink is disabled. So fix this by having a check for coresight sysfs mode before reading TMC mode management register in tmc_read_unprepare_etb() similar to tmc_read_prepare_etb(). SError Interrupt on CPU6, code 0xbe000411 -- SError pstate: 80400089 (Nzcv daIf +PAN -UAO) pc : tmc_read_unprepare_etb+0x74/0x108 lr : tmc_read_unprepare_etb+0x54/0x108 sp : ffffff80d9507c30 x29: ffffff80d9507c30 x28: ffffff80b3569a0c x27: 0000000000000000 x26: 00000000000a0001 x25: ffffff80cbae9550 x24: 0000000000000010 x23: ffffffd07296b0f0 x22: ffffffd0109ee028 x21: 0000000000000000 x20: ffffff80d19e70e0 x19: ffffff80d19e7080 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: dfffffd000000001 x9 : 0000000000000000 x8 : 0000000000000002 x7 : ffffffd071d0fe78 x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000001 x3 : ffffffd071d0fe98 x2 : 0000000000000000 x1 : 0000000000000004 x0 : 0000000000000001 Kernel panic - not syncing: Asynchronous SError Interrupt
Unified · Split
| @@ -639,15 +639,14 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) · 638 unmodified lines | ||
| 639 | 639 | |
| 640 | 640 | spin_lock_irqsave(&drvdata->spinlock, flags); |
| 641 | 641 | |
| 642 | − /* There is no point in reading a TMC in HW FIFO mode */ | |
| 643 | − mode = readl_relaxed(drvdata->base + TMC_MODE); | |
| 644 | − if (mode != TMC_MODE_CIRCULAR_BUFFER) { | |
| 645 | − spin_unlock_irqrestore(&drvdata->spinlock, flags); | |
| 646 | − return -EINVAL; | |
| 647 | − } | |
| 648 | − | |
| 649 | 642 | /* Re-enable the TMC if need be */ |
| 650 | 643 | if (drvdata->mode == CS_MODE_SYSFS) { |
| 644 | + /* There is no point in reading a TMC in HW FIFO mode */ | |
| 645 | + mode = readl_relaxed(drvdata->base + TMC_MODE); | |
| 646 | + if (mode != TMC_MODE_CIRCULAR_BUFFER) { | |
| 647 | + spin_unlock_irqrestore(&drvdata->spinlock, flags); | |
| 648 | + return -EINVAL; | |
| 649 | + } | |
| 651 | 650 | /* |
| 652 | 651 | * The trace run will continue with the same allocated trace |
| 653 | 652 | * buffer. As such zero-out the buffer so that we don't end |