arcmsr: clear outbound doorbell buffer completely

Clear outbound doorbell buffer completely for adapter type C.  This is to
prevent getting bad data input from IOP before ioctl command processing
starts.

Signed-off-by: Ching Huang <ching2048@areca.com.tw>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 14 insertions, 4 deletions

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 0707677c11a1..3363c31bb789 100644
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2870,11 +2870,23 @@ static void arcmsr_clear_doorbell_queue_buffer(struct AdapterControlBlock *acb)
                 break;
         case ACB_ADAPTER_TYPE_C: {
                 struct MessageUnit_C *reg = (struct MessageUnit_C *)acb->pmuC;
-                uint32_t outbound_doorbell;
+                uint32_t outbound_doorbell, i;
                 /* empty doorbell Qbuffer if door bell ringed */
                 outbound_doorbell = readl(&reg->outbound_doorbell);
                 writel(outbound_doorbell, &reg->outbound_doorbell_clear);
                 writel(ARCMSR_HBCMU_DRV2IOP_DATA_READ_OK, &reg->inbound_doorbell);
+                for (i = 0; i < 200; i++) {
+                        msleep(20);
+                        outbound_doorbell = readl(&reg->outbound_doorbell);
+                        if (outbound_doorbell &
+                                ARCMSR_HBCMU_IOP2DRV_DATA_WRITE_OK) {
+                                writel(outbound_doorbell,
+                                        &reg->outbound_doorbell_clear);
+                                writel(ARCMSR_HBCMU_DRV2IOP_DATA_READ_OK,
+                                        &reg->inbound_doorbell);
+                        } else
+                                break;
+                }
                 }
         }
 }
@@ -3102,9 +3114,7 @@ sleep:
                                 arcmsr_get_firmware_spec(acb);
                                 arcmsr_start_adapter_bgrb(acb);
                                 /* clear Qbuffer if door bell ringed */
-                                outbound_doorbell = readl(&reg->outbound_doorbell);
-                                writel(outbound_doorbell, &reg->outbound_doorbell_clear); /*clear interrupt */
-                                writel(ARCMSR_HBCMU_DRV2IOP_DATA_READ_OK, &reg->inbound_doorbell);
+                                arcmsr_clear_doorbell_queue_buffer(acb);
                                 /* enable outbound Post Queue,outbound doorbell Interrupt */
                                 arcmsr_enable_outbound_ints(acb, intmask_org);
                                 atomic_set(&acb->rq_map_token, 16);