Re: [PATCH] crypto: hisilicon - check if debugfs opened

From: tanghui20
Date: Tue Mar 30 2021 - 08:41:22 EST




On 2021/3/30 20:23, Greg KH wrote:
On Tue, Mar 30, 2021 at 08:09:46PM +0800, tanghui20 wrote:


On 2021/3/28 23:09, Greg KH wrote:
On Sat, Mar 27, 2021 at 04:33:00PM +0800, Hui Tang wrote:
'xx_debugfs_init' check if debugfs opened.

Signed-off-by: Hui Tang <tanghui20@xxxxxxxxxx>
---
drivers/crypto/hisilicon/hpre/hpre_main.c | 5 ++++-
drivers/crypto/hisilicon/qm.c | 3 +++
drivers/crypto/hisilicon/sec2/sec_main.c | 5 ++++-
drivers/crypto/hisilicon/zip/zip_main.c | 3 +++
4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/hisilicon/hpre/hpre_main.c b/drivers/crypto/hisilicon/hpre/hpre_main.c
index c7ab06d..f2605c4 100644
--- a/drivers/crypto/hisilicon/hpre/hpre_main.c
+++ b/drivers/crypto/hisilicon/hpre/hpre_main.c
@@ -779,6 +779,9 @@ static int hpre_debugfs_init(struct hisi_qm *qm)
struct device *dev = &qm->pdev->dev;
int ret;

+ if (!debugfs_initialized())
+ return -ENOENT;

Why? What does this help with? Why does the code care if debugfs is
running or not?

When !CONFIG_DEBUG_FS, there is no problem if debugfs is not checked,
but if checking debugfs, a series of stub functions of debugfs can be
skipped and 'xx_debugfs_init' will be return immediately.

And have you measured an actual speed difference for that? I would be
amazed if you could...


I think what you said makes sense.
I am confused when to use 'debugfs_initialized'.

Thanks