scsi: arcmsr: Fix doorbell status being updated late on ARC-1886

[ Upstream commit d9a231226f28261a787535e08d0c78669e1ad010 ]

It is possible for the IOP to be delayed in updating the doorbell
status. The doorbell status should not be 0 so loop until the value
changes.

Link: https://lore.kernel.org/r/afdfdf7eabecf14632492c4987a6b9ac6312a7ad.camel@areca.com.tw
Signed-off-by: ching Huang <ching2048@areca.com.tw>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 4838f79..9294a2c 100644 (file)
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2424,10 +2424,17 @@ static void arcmsr_hbaD_doorbell_isr(struct AdapterControlBlock *pACB)
 
 static void arcmsr_hbaE_doorbell_isr(struct AdapterControlBlock *pACB)
 {
-       uint32_t outbound_doorbell, in_doorbell, tmp;
+       uint32_t outbound_doorbell, in_doorbell, tmp, i;
        struct MessageUnit_E __iomem *reg = pACB->pmuE;
 
-       in_doorbell = readl(&reg->iobound_doorbell);
+       if (pACB->adapter_type == ACB_ADAPTER_TYPE_F) {
+               for (i = 0; i < 5; i++) {
+                       in_doorbell = readl(&reg->iobound_doorbell);
+                       if (in_doorbell != 0)
+                               break;
+               }
+       } else
+               in_doorbell = readl(&reg->iobound_doorbell);
        outbound_doorbell = in_doorbell ^ pACB->in_doorbell;
        do {
                writel(0, &reg->host_int_status); /* clear interrupt */