[PATCH 5.12 105/173] usb: cdnsp: Fix deadlock issue in cdnsp_thread_irq_handler

From: Greg Kroah-Hartman
Date: Mon Jun 14 2021 - 07:35:12 EST


From: Pawel Laszczak <pawell@xxxxxxxxxxx>

commit a9aecef198faae3240921b707bc09b602e966fce upstream.

Patch fixes the following critical issue caused by deadlock which has been
detected during testing NCM class:

smp: csd: Detected non-responsive CSD lock (#1) on CPU#0
smp: csd: CSD lock (#1) unresponsive.
....
RIP: 0010:native_queued_spin_lock_slowpath+0x61/0x1d0
RSP: 0018:ffffbc494011cde0 EFLAGS: 00000002
RAX: 0000000000000101 RBX: ffff9ee8116b4a68 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ee8116b4658
RBP: ffffbc494011cde0 R08: 0000000000000001 R09: 0000000000000000
R10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658
R13: ffff9ee8116b4670 R14: 0000000000000246 R15: ffff9ee8116b4658
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7bcc41a830 CR3: 000000007a612003 CR4: 00000000001706e0
Call Trace:
<IRQ>
do_raw_spin_lock+0xc0/0xd0
_raw_spin_lock_irqsave+0x95/0xa0
cdnsp_gadget_ep_queue.cold+0x88/0x107 [cdnsp_udc_pci]
usb_ep_queue+0x35/0x110
eth_start_xmit+0x220/0x3d0 [u_ether]
ncm_tx_timeout+0x34/0x40 [usb_f_ncm]
? ncm_free_inst+0x50/0x50 [usb_f_ncm]
__hrtimer_run_queues+0xac/0x440
hrtimer_run_softirq+0x8c/0xb0
__do_softirq+0xcf/0x428
asm_call_irq_on_stack+0x12/0x20
</IRQ>
do_softirq_own_stack+0x61/0x70
irq_exit_rcu+0xc1/0xd0
sysvec_apic_timer_interrupt+0x52/0xb0
asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:do_raw_spin_trylock+0x18/0x40
RSP: 0018:ffffbc494138bda8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff9ee8116b4658 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9ee8116b4658
RBP: ffffbc494138bda8 R08: 0000000000000001 R09: 0000000000000000
R10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658
R13: ffff9ee8116b4670 R14: ffff9ee7b5c73d80 R15: ffff9ee8116b4000
_raw_spin_lock+0x3d/0x70
? cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci]
cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci]
? cdnsp_remove_request+0x1f0/0x1f0 [cdnsp_udc_pci]
? cdnsp_thread_irq_handler+0x5/0xa0 [cdnsp_udc_pci]
? irq_thread+0xa0/0x1c0
irq_thread_fn+0x28/0x60
irq_thread+0x105/0x1c0
? __kthread_parkme+0x42/0x90
? irq_forced_thread_fn+0x90/0x90
? wake_threads_waitq+0x30/0x30
? irq_thread_check_affinity+0xe0/0xe0
kthread+0x12a/0x160
? kthread_park+0x90/0x90
ret_from_fork+0x22/0x30

The root cause of issue is spin_lock/spin_unlock instruction instead
spin_lock_irqsave/spin_lock_irqrestore in cdnsp_thread_irq_handler
function.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210526060527.7197-1-pawell@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/cdns3/cdnsp-ring.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1517,13 +1517,14 @@ irqreturn_t cdnsp_thread_irq_handler(int
{
struct cdnsp_device *pdev = (struct cdnsp_device *)data;
union cdnsp_trb *event_ring_deq;
+ unsigned long flags;
int counter = 0;

- spin_lock(&pdev->lock);
+ spin_lock_irqsave(&pdev->lock, flags);

if (pdev->cdnsp_state & (CDNSP_STATE_HALTED | CDNSP_STATE_DYING)) {
cdnsp_died(pdev);
- spin_unlock(&pdev->lock);
+ spin_unlock_irqrestore(&pdev->lock, flags);
return IRQ_HANDLED;
}

@@ -1539,7 +1540,7 @@ irqreturn_t cdnsp_thread_irq_handler(int

cdnsp_update_erst_dequeue(pdev, event_ring_deq, 1);

- spin_unlock(&pdev->lock);
+ spin_unlock_irqrestore(&pdev->lock, flags);

return IRQ_HANDLED;
}