From: Meng Li Meng.Li@windriver.com
commit dc7e5940aad6641bd5ab33ea8b21c4b3904d989f upstream.
In orininal code, use 2 function spin_lock() and local_irq_save() to protect the critical zone. But when enable the kernel debug config, there are below inconsistent lock state detected. ================================ WARNING: inconsistent lock state 5.10.63-yocto-standard #1 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. lock_torture_wr/226 [HC0[0]:SC1[5]:HE1:SE0] takes: ffff002005b2dd80 (&p->access_spinlock){+.?.}-{3:3}, at: qbman_swp_enqueue_multiple_mem_back+0x44/0x270 {SOFTIRQ-ON-W} state was registered at: lock_acquire.part.0+0xf8/0x250 lock_acquire+0x68/0x84 _raw_spin_lock+0x68/0x90 qbman_swp_enqueue_multiple_mem_back+0x44/0x270 ...... cryptomgr_test+0x38/0x60 kthread+0x158/0x164 ret_from_fork+0x10/0x38 irq event stamp: 4498 hardirqs last enabled at (4498): [<ffff800010fcf980>] _raw_spin_unlock_irqrestore+0x90/0xb0 hardirqs last disabled at (4497): [<ffff800010fcffc4>] _raw_spin_lock_irqsave+0xd4/0xe0 softirqs last enabled at (4458): [<ffff8000100108c4>] __do_softirq+0x674/0x724 softirqs last disabled at (4465): [<ffff80001005b2a4>] __irq_exit_rcu+0x190/0x19c
other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&p->access_spinlock); <Interrupt> lock(&p->access_spinlock); *** DEADLOCK ***
So, in order to avoid deadlock, use the combined functions spin_lock_irqsave/spin_unlock_irqrestore() to protect critical zone.
Fixes: 3b2abda7d28c ("soc: fsl: dpio: Replace QMAN array mode with ring mode enqueue") Cc: stable@vger.kernel.org Signed-off-by: Meng Li Meng.Li@windriver.com Signed-off-by: Li Yang leoyang.li@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/soc/fsl/dpio/qbman-portal.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
--- a/drivers/soc/fsl/dpio/qbman-portal.c +++ b/drivers/soc/fsl/dpio/qbman-portal.c @@ -732,8 +732,7 @@ int qbman_swp_enqueue_multiple_mem_back( int i, num_enqueued = 0; unsigned long irq_flags;
- spin_lock(&s->access_spinlock); - local_irq_save(irq_flags); + spin_lock_irqsave(&s->access_spinlock, irq_flags);
half_mask = (s->eqcr.pi_ci_mask>>1); full_mask = s->eqcr.pi_ci_mask; @@ -744,8 +743,7 @@ int qbman_swp_enqueue_multiple_mem_back( s->eqcr.available = qm_cyc_diff(s->eqcr.pi_ring_size, eqcr_ci, s->eqcr.ci); if (!s->eqcr.available) { - local_irq_restore(irq_flags); - spin_unlock(&s->access_spinlock); + spin_unlock_irqrestore(&s->access_spinlock, irq_flags); return 0; } } @@ -784,8 +782,7 @@ int qbman_swp_enqueue_multiple_mem_back( dma_wmb(); qbman_write_register(s, QBMAN_CINH_SWP_EQCR_PI, (QB_RT_BIT)|(s->eqcr.pi)|s->eqcr.pi_vb); - local_irq_restore(irq_flags); - spin_unlock(&s->access_spinlock); + spin_unlock_irqrestore(&s->access_spinlock, irq_flags);
return num_enqueued; }