From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit a89d69a44e282be95ae76125dddc79515541efeb ]
Since 2431c4f5b46c3 ("mtd: Implement mtd_{read,write}() as wrappers around mtd_{read,write}_oob()") don't allow _write|_read and _write_oob|_read_oob existing at the same time, we should check the existence of callbacks "_read and _write" from subdev's master device (We can trust master device since it has been registered) before assigning, otherwise following warning occurs while making concatenated device:
WARNING: CPU: 2 PID: 6728 at drivers/mtd/mtdcore.c:595 add_mtd_device+0x7f/0x7b0
Fixes: 2431c4f5b46c3 ("mtd: Implement mtd_{read,write}() around ...") Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Link: https://lore.kernel.org/linux-mtd/20210817114857.2784825-3-chengzhihao1@huaw... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/mtdconcat.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c index af51eee6b5e8..f685a581df48 100644 --- a/drivers/mtd/mtdconcat.c +++ b/drivers/mtd/mtdconcat.c @@ -694,6 +694,10 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c concat->mtd._block_markbad = concat_block_markbad; if (subdev_master->_panic_write) concat->mtd._panic_write = concat_panic_write; + if (subdev_master->_read) + concat->mtd._read = concat_read; + if (subdev_master->_write) + concat->mtd._write = concat_write;
concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
@@ -755,8 +759,6 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c concat->mtd.name = name;
concat->mtd._erase = concat_erase; - concat->mtd._read = concat_read; - concat->mtd._write = concat_write; concat->mtd._sync = concat_sync; concat->mtd._lock = concat_lock; concat->mtd._unlock = concat_unlock;