mtd: Fix misuses of of_match_ptr()

of_match_ptr() either expands to NULL if !CONFIG_OF, or is transparent
otherwise. There are several drivers using this macro which keep their
of_device_id array enclosed within an #ifdef CONFIG_OF check, these are
considered fine. However, When misused, the of_device_id array pointed
by this macro will produce a warning because it is finally unused when
compiled without OF support.

A number of fixes are possible:
- Always depend on CONFIG_OF, but this will not always work and may
  break boards.
- Enclose the compatible array by #ifdef's, this may save a bit of
  memory but will reduce build coverage.
- Tell the compiler the array may be unused, if this can be avoided,
  let's not do this.
- Just drop the macro, setting the of_device_id array for a non OF
  enabled platform is not an issue, it will just be unused.

The latter solution seems the more appropriate, so let's use it.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/linux-mtd/20220127110631.1064705-1-miquel.raynal@bootlin.com

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
index f3276ee9e4fe..4ecbaccf5526 100644
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c
+++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
@@ -2648,7 +2648,7 @@ static SIMPLE_DEV_PM_OPS(atmel_nand_controller_pm_ops, NULL,
 static struct platform_driver atmel_nand_controller_driver = {
 	.driver = {
 		.name = "atmel-nand-controller",
-		.of_match_table = of_match_ptr(atmel_nand_controller_of_ids),
+		.of_match_table = atmel_nand_controller_of_ids,
 		.pm = &atmel_nand_controller_pm_ops,
 	},
 	.probe = atmel_nand_controller_probe,
diff --git a/drivers/mtd/nand/raw/atmel/pmecc.c b/drivers/mtd/nand/raw/atmel/pmecc.c
index 498e41ccabbd..43ebd78816c0 100644
--- a/drivers/mtd/nand/raw/atmel/pmecc.c
+++ b/drivers/mtd/nand/raw/atmel/pmecc.c
@@ -1003,7 +1003,7 @@ static int atmel_pmecc_probe(struct platform_device *pdev)
 static struct platform_driver atmel_pmecc_driver = {
 	.driver = {
 		.name = "atmel-pmecc",
-		.of_match_table = of_match_ptr(atmel_pmecc_match),
+		.of_match_table = atmel_pmecc_match,
 	},
 	.probe = atmel_pmecc_probe,
 };