[PATCH] cxl/mem: Fix an error code in cxl_mem_mbox_get()

[Dan Carpenter]

Smatch complains that sometimes when we return success we are holding
the mutex and sometimes we have released the mutex.  It turns out that
the bug is a missing error code if the mbox is not ready.  It should
return -EBUSY instead of success.

Fixes: cc1967ac93ab ("cxl/mem: Find device capabilities")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
 drivers/cxl/mem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 3bca8451348a..2ebc84e4d202 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -383,8 +383,8 @@ static int __cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm,
 static int cxl_mem_mbox_get(struct cxl_mem *cxlm)
 {
        struct device *dev = &cxlm->pdev->dev;
-       int rc = -EBUSY;
        u64 md_status;
+       int rc;
 
        mutex_lock_io(&cxlm->mbox_mutex);
 
@@ -414,6 +414,7 @@ static int cxl_mem_mbox_get(struct cxl_mem *cxlm)
        md_status = readq(cxlm->memdev_regs + CXLMDEV_STATUS_OFFSET);
        if (!(md_status & CXLMDEV_MBOX_IF_READY && CXLMDEV_READY(md_status))) {
                dev_err(dev, "mbox: reported doorbell ready, but not mbox 
ready\n");
+               rc = -EBUSY;
                goto out;
        }
 
-- 
2.30.0