The bus master was not removed after unloading the module or unbinding the driver. That lead to oopses like this

[ 127.842987] Unable to handle kernel paging request at virtual address bf01d04c [ 127.850646] pgd = 70e3cd9a [ 127.853698] [bf01d04c] *pgd=8f908811, *pte=00000000, *ppte=00000000 [ 127.860412] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM [ 127.866668] Modules linked in: bq27xxx_battery overlay [last unloaded: omap_hdq] [ 127.874542] CPU: 0 PID: 1022 Comm: w1_bus_master1 Not tainted 4.19.0-rc4-00001-g2d51da718324 #12 [ 127.883819] Hardware name: Generic OMAP36xx (Flattened Device Tree) [ 127.890441] PC is at 0xbf01d04c [ 127.893798] LR is at w1_search_process_cb+0x4c/0xfc [ 127.898956] pc : [<bf01d04c>] lr : [<c05f9580>] psr: a0070013 [ 127.905609] sp : cf885f48 ip : bf01d04c fp : ddf1e11c [ 127.911132] r10: cf8fe040 r9 : c05f8d00 r8 : cf8fe040 [ 127.916656] r7 : 000000f0 r6 : cf8fe02c r5 : cf8fe000 r4 : cf8fe01c [ 127.923553] r3 : c05f8d00 r2 : 000000f0 r1 : cf8fe000 r0 : dde1ef10 [ 127.930450] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 127.938018] Control: 10c5387d Table: 8f8f0019 DAC: 00000051 [ 127.944091] Process w1_bus_master1 (pid: 1022, stack limit = 0x9135699f) [ 127.951171] Stack: (0xcf885f48 to 0xcf886000) [ 127.955810] 5f40: cf8fe000 00000000 cf884000 cf8fe090 000003e8 c05f8d00 [ 127.964477] 5f60: dde5fc34 c05f9700 ddf1e100 ddf1e540 cf884000 cf8fe000 c05f9694 00000000 [ 127.973114] 5f80: dde5fc34 c01499a4 00000000 ddf1e540 c0149874 00000000 00000000 00000000 [ 127.981781] 5fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000 [ 127.990447] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 127.999114] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [ 128.007781] [<c05f9580>] (w1_search_process_cb) from [<c05f9700>] (w1_process+0x6c/0x118) [ 128.016479] [<c05f9700>] (w1_process) from [<c01499a4>] (kthread+0x130/0x148) [ 128.024047] [<c01499a4>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c) [ 128.031677] Exception stack(0xcf885fb0 to 0xcf885ff8) [ 128.037017] 5fa0: 00000000 00000000 00000000 00000000 [ 128.045684] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 128.054351] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 128.061340] Code: bad PC value [ 128.064697] ---[ end trace af066e33c0e14119 ]---

Cc: stable@vger.kernel.org Signed-off-by: Andreas Kemnade andreas@kemnade.info --- drivers/w1/masters/omap_hdq.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c index 83fc9aab34e8..3099052e1243 100644 --- a/drivers/w1/masters/omap_hdq.c +++ b/drivers/w1/masters/omap_hdq.c @@ -763,6 +763,8 @@ static int omap_hdq_remove(struct platform_device *pdev) /* remove module dependency */ pm_runtime_disable(&pdev->dev);

+ w1_remove_master_device(&omap_w1_master); + return 0; }