diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index c148f76dd8e2..bfab719190e8 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -419,6 +419,7 @@ /* High-level queue structures */ #define ARM_SMMU_POLL_TIMEOUT_US 100 #define ARM_SMMU_CMDQ_SYNC_TIMEOUT_US 1000000 /* 1s! */ +#define ARM_SMMU_CMDQ_SYNC_SPIN_COUNT 10 #define MSI_IOVA_BASE 0x8000000 #define MSI_IOVA_LENGTH 0x100000 @@ -769,7 +770,7 @@ static void queue_inc_prod(struct arm_smmu_queue *q) static int queue_poll_cons(struct arm_smmu_queue *q, bool sync, bool wfe) { ktime_t timeout; - unsigned int delay = 1; + unsigned int delay = 1, spin_cnt = 0; /* Wait longer if it's a CMD_SYNC */ timeout = ktime_add_us(ktime_get(), sync ? @@ -782,10 +783,13 @@ static int queue_poll_cons(struct arm_smmu_queue *q, bool sync, bool wfe) if (wfe) { wfe(); - } else { + } else if (++spin_cnt < ARM_SMMU_CMDQ_SYNC_SPIN_COUNT) { cpu_relax(); + continue; + } else { udelay(delay); delay *= 2; + spin_cnt = 0; } } |