@@ -318,15 +318,16 @@ static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
static int smp2p_update_bits(void *data, u32 mask, u32 value)
{
struct smp2p_entry *entry = data;
+ unsigned long flags;
u32 orig;
u32 val;
- spin_lock(&entry->lock);
+ spin_lock_irqsave(&entry->lock, flags);
val = orig = readl(entry->value);
val &= ~mask;
val |= value;
writel(val, entry->value);
- spin_unlock(&entry->lock);
+ spin_unlock_irqrestore(&entry->lock, flags);
if (val != orig)
qcom_smp2p_kick(entry->smp2p);
smp2p_update_bits() should disable interrupts when it acquires its spinlock. This is important because without the _irqsave, a priority inversion can occur. This function is called both with interrupts enabled in qcom_q6v5_request_stop(), and with interrupts disabled in ipa_smp2p_panic_notifier(). IRQ handling of spinlocks should be consistent to avoid the panic notifier deadlocking because it's sitting on the thread that's already got the lock via _request_stop(). Found via lockdep. Fixes: 50e99641413e7 ("soc: qcom: smp2p: Qualcomm Shared Memory Point to Point") Signed-off-by: Evan Green <evgreen@chromium.org> --- drivers/soc/qcom/smp2p.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)