[PATCH 05/14] skd: register block device only if some devices arepresent

[Bartlomiej Zolnierkiewicz]

Register block device in skd_pci_probe() instead of in skd_init() so it
is registered only if some devices are present (currently it is always
registered when the driver is loaded). Please note that this change
depends on the fact that register_blkdev(0, ...) never returns 0.

Cc: Akhil Bhansali <abhansali@xxxxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
 drivers/block/skd_main.c | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index e63a63c..738f847 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -5215,6 +5215,14 @@ static int skd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		}
 	}
 
+	if (!skd_major) {
+		rc = register_blkdev(0, DRV_NAME);
+		if (rc < 0)
+			goto err_out_regions;
+		BUG_ON(!rc);
+		skd_major = rc;
+	}
+
 	skdev = skd_construct(pdev);
 	if (skdev == NULL)
 		goto err_out_regions;
@@ -5711,8 +5719,6 @@ static void skd_log_skreq(struct skd_device *skdev,
 
 static int __init skd_init(void)
 {
-	int rc = -ENOMEM;
-
 	pr_info(PFX " v%s-b%s loaded\n", DRV_VERSION, DRV_BUILD_ID);
 
 	switch (skd_isr_type) {
@@ -5763,24 +5769,7 @@ static int __init skd_init(void)
 		skd_max_pass_thru = SKD_N_SPECIAL_CONTEXT;
 	}
 
-	/* Obtain major device number. */
-	rc = register_blkdev(0, DRV_NAME);
-	if (rc < 0)
-		goto err_register_blkdev;
-
-	skd_major = rc;
-
-	rc = pci_register_driver(&skd_driver);
-	if (rc < 0)
-		goto err_pci_register_driver;
-
-	return rc;
-
-err_pci_register_driver:
-	unregister_blkdev(skd_major, DRV_NAME);
-
-err_register_blkdev:
-	return rc;
+	return pci_register_driver(&skd_driver);
 }
 
 static void __exit skd_exit(void)
@@ -5789,7 +5778,8 @@ static void __exit skd_exit(void)
 
 	pci_unregister_driver(&skd_driver);
 
-	unregister_blkdev(skd_major, DRV_NAME);
+	if (skd_major)
+		unregister_blkdev(skd_major, DRV_NAME);
 
 	if (skd_flush_slab)
 		kmem_cache_destroy(skd_flush_slab);
-- 
1.8.2.3

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