[PATCH] mtd: nand: diskonchip: Replace mdelay with usleep_range in doc_probe

From: Jia-Ju Bai
Date: Tue Apr 10 2018 - 22:58:14 EST


doc_probe() is never called in atomic context.

doc_probe() is only called by init_nanddoc(), which is only set as
a parameter of module_init().
This function is not called in atomic context.

Despite never getting called from atomic context, doc_probe()
calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range() to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/mtd/nand/diskonchip.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/diskonchip.c b/drivers/mtd/nand/diskonchip.c
index c3aa53c..2679bc4 100644
--- a/drivers/mtd/nand/diskonchip.c
+++ b/drivers/mtd/nand/diskonchip.c
@@ -1482,12 +1482,12 @@ static int __init doc_probe(unsigned long physadr)
WriteDOC(tmp, virtadr, Mplus_DOCControl);
WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);

- mdelay(1);
+ usleep_range(1000, 2000);
/* Enable the Millennium Plus ASIC */
tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | DOC_MODE_BDECT;
WriteDOC(tmp, virtadr, Mplus_DOCControl);
WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);
- mdelay(1);
+ usleep_range(1000, 2000);

ChipID = ReadDOC(virtadr, ChipID);

--
1.9.1