* [PATCH] [v2] usb: musb: Fix runtime PM imbalance on error
@ 2020-05-22 2:59 Dinghao Liu
2020-05-22 5:12 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Dinghao Liu @ 2020-05-22 2:59 UTC (permalink / raw)
To: dinghao.liu, kjlu; +Cc: Bin Liu, Greg Kroah-Hartman, linux-usb, linux-kernel
When copy_from_user() returns an error code, there
is a runtime PM usage counter imbalance.
Fix this by moving copy_from_user() to the beginning
of this function.
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
---
drivers/usb/musb/musb_debugfs.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 7b6281ab62ed..30a89aa8a3e7 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -168,6 +168,11 @@ static ssize_t musb_test_mode_write(struct file *file,
u8 test;
char buf[24];
+ memset(buf, 0x00, sizeof(buf));
+
+ if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+ return -EFAULT;
+
pm_runtime_get_sync(musb->controller);
test = musb_readb(musb->mregs, MUSB_TESTMODE);
if (test) {
@@ -176,11 +181,6 @@ static ssize_t musb_test_mode_write(struct file *file,
goto ret;
}
- memset(buf, 0x00, sizeof(buf));
-
- if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
- return -EFAULT;
-
if (strstarts(buf, "force host full-speed"))
test = MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_FS;
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] [v2] usb: musb: Fix runtime PM imbalance on error
2020-05-22 2:59 [PATCH] [v2] usb: musb: Fix runtime PM imbalance on error Dinghao Liu
@ 2020-05-22 5:12 ` Greg Kroah-Hartman
2020-05-22 5:22 ` dinghao.liu
0 siblings, 1 reply; 4+ messages in thread
From: Greg Kroah-Hartman @ 2020-05-22 5:12 UTC (permalink / raw)
To: Dinghao Liu; +Cc: kjlu, Bin Liu, linux-usb, linux-kernel
On Fri, May 22, 2020 at 10:59:02AM +0800, Dinghao Liu wrote:
> When copy_from_user() returns an error code, there
> is a runtime PM usage counter imbalance.
>
> Fix this by moving copy_from_user() to the beginning
> of this function.
>
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
> drivers/usb/musb/musb_debugfs.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
What changed from v1? Always show that below the --- line as the
documentation says to.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Re: [PATCH] [v2] usb: musb: Fix runtime PM imbalance on error
2020-05-22 5:12 ` Greg Kroah-Hartman
@ 2020-05-22 5:22 ` dinghao.liu
2020-05-22 5:32 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: dinghao.liu @ 2020-05-22 5:22 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: kjlu, Bin Liu, linux-usb, linux-kernel
Sorry, it's my carelessness. In v1 I added pm_runtime_put_autosuspend()
after copy_from_user() to fix this problem. Since copy_from_user() is
moved to the beginning now, we need not to add PM decrement.
Regards,
Dinghao
> On Fri, May 22, 2020 at 10:59:02AM +0800, Dinghao Liu wrote:
> > When copy_from_user() returns an error code, there
> > is a runtime PM usage counter imbalance.
> >
> > Fix this by moving copy_from_user() to the beginning
> > of this function.
> >
> > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> > ---
> > drivers/usb/musb/musb_debugfs.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
>
> What changed from v1? Always show that below the --- line as the
> documentation says to.
>
> thanks,
>
> greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Re: [PATCH] [v2] usb: musb: Fix runtime PM imbalance on error
2020-05-22 5:22 ` dinghao.liu
@ 2020-05-22 5:32 ` Greg Kroah-Hartman
0 siblings, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2020-05-22 5:32 UTC (permalink / raw)
To: dinghao.liu; +Cc: kjlu, Bin Liu, linux-usb, linux-kernel
On Fri, May 22, 2020 at 01:22:24PM +0800, dinghao.liu@zju.edu.cn wrote:
> Sorry, it's my carelessness. In v1 I added pm_runtime_put_autosuspend()
> after copy_from_user() to fix this problem. Since copy_from_user() is
> moved to the beginning now, we need not to add PM decrement.
THat's fine, please put that information in a v3 and resend it.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-05-22 2:59 [PATCH] [v2] usb: musb: Fix runtime PM imbalance on error Dinghao Liu
2020-05-22 5:12 ` Greg Kroah-Hartman
2020-05-22 5:22 ` dinghao.liu
2020-05-22 5:32 ` Greg Kroah-Hartman
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