Patch "scsi: arcmsr: Fix doorbell status being updated late on ARC-1886" has been added to the 5.13-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 5.13-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-arcmsr-fix-doorbell-status-being-updated-late-o.patch
and it can be found in the queue-5.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2aa51911480308e96a5681c1cf4a71badc11512d
Author: ching Huang <ching2048@xxxxxxxxxxxx>
Date:   Thu May 20 14:55:15 2021 +0800

    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@xxxxxxxxxxxx
    Signed-off-by: ching Huang <ching2048@xxxxxxxxxxxx>
    Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index 930972cda38c..42e494a7106c 100644
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -2419,10 +2419,17 @@ 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 */