* [PATCH] usb: misc: chaoskey: get lock before calling usb_[disable|enable]_autosuspend()
@ 2021-08-02 22:22 Salah Triki
2021-08-03 0:58 ` Alan Stern
0 siblings, 1 reply; 2+ messages in thread
From: Salah Triki @ 2021-08-02 22:22 UTC (permalink / raw)
To: Keith Packard, Greg Kroah-Hartman; +Cc: linux-usb, linux-kernel
Based on the documentation of usb_[disable|enable]_autosuspend(), the
caller must hold udev's device lock.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
---
drivers/usb/misc/chaoskey.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index 87067c3d6109..8af00be7b9e8 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -206,7 +206,9 @@ static int chaoskey_probe(struct usb_interface *interface,
if (!dev->hwrng_registered)
usb_err(interface, "Unable to register with hwrng");
+ usb_lock_device(udev);
usb_enable_autosuspend(udev);
+ usb_unlock_device(udev);
usb_dbg(interface, "chaoskey probe success, size %d", dev->size);
return 0;
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] usb: misc: chaoskey: get lock before calling usb_[disable|enable]_autosuspend()
2021-08-02 22:22 [PATCH] usb: misc: chaoskey: get lock before calling usb_[disable|enable]_autosuspend() Salah Triki
@ 2021-08-03 0:58 ` Alan Stern
0 siblings, 0 replies; 2+ messages in thread
From: Alan Stern @ 2021-08-03 0:58 UTC (permalink / raw)
To: Salah Triki; +Cc: Keith Packard, Greg Kroah-Hartman, linux-usb, linux-kernel
On Mon, Aug 02, 2021 at 11:22:05PM +0100, Salah Triki wrote:
> Based on the documentation of usb_[disable|enable]_autosuspend(), the
> caller must hold udev's device lock.
>
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> ---
> drivers/usb/misc/chaoskey.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
> index 87067c3d6109..8af00be7b9e8 100644
> --- a/drivers/usb/misc/chaoskey.c
> +++ b/drivers/usb/misc/chaoskey.c
> @@ -206,7 +206,9 @@ static int chaoskey_probe(struct usb_interface *interface,
> if (!dev->hwrng_registered)
> usb_err(interface, "Unable to register with hwrng");
>
> + usb_lock_device(udev);
> usb_enable_autosuspend(udev);
> + usb_unlock_device(udev);
Not needed (indeed, actively harmful). When this code runs it already
holds the device lock, because it is part of a probe routine.
Alan Stern
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-08-02 22:22 [PATCH] usb: misc: chaoskey: get lock before calling usb_[disable|enable]_autosuspend() Salah Triki
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