From d64a59b72985220f9d29fd8dd447a183375bde00 Mon Sep 17 00:00:00 2001
From: Thomas Glanzmann <thomas@glanzmann.de>
Date: Sun, 20 Mar 2022 14:14:36 +0100
Subject: [PATCH] 13:37 < sven> Glanzmann: can you try what happens when you
 have no spinlock but add a readl(q->sq_db); just after the writel(tag,
 q->sq_db);?

---
 drivers/nvme/host/apple.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/nvme/host/apple.c b/drivers/nvme/host/apple.c
index 3e1c32041..567f7542f 100644
--- a/drivers/nvme/host/apple.c
+++ b/drivers/nvme/host/apple.c
@@ -327,6 +327,7 @@ static void apple_nvme_submit_cmd(struct apple_nvme_queue *q,
 
 	memcpy(&q->sqes[tag], cmd, sizeof(*cmd));
 	writel(tag, q->sq_db);
+        dma_mb();
 }
 
 /*
-- 
2.30.2