Hi Greg, On 24/08/21 6:36 pm, Greg Kroah-Hartman wrote: > On Tue, Aug 24, 2021 at 04:22:58PM +0530, Kishon Vijay Abraham I wrote: >> No functional change. Since configuration to stop HCD is invoked from >> multiple places, group all of them in usb_stop_hcd(). >> >> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> >> --- >> drivers/usb/core/hcd.c | 42 +++++++++++++++++++++++++----------------- >> 1 file changed, 25 insertions(+), 17 deletions(-) >> >> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c >> index 0f8b7c93310e..c036ba5311b3 100644 >> --- a/drivers/usb/core/hcd.c >> +++ b/drivers/usb/core/hcd.c >> @@ -2760,6 +2760,29 @@ static void usb_put_invalidate_rhdev(struct usb_hcd *hcd) >> usb_put_dev(rhdev); >> } >> >> +/** >> + * usb_stop_hcd - Halt the HCD >> + * @hcd: the usb_hcd that has to be halted >> + * >> + * Stop the timer and invoke ->stop() callback on the HCD >> + */ >> +static void usb_stop_hcd(struct usb_hcd *hcd) >> +{ >> + if (!hcd) >> + return; > > That's impossible to hit, so no need to check for it, right? Patch 3 of this series adds support for registering roothub of shared HCD. So after that patch there can be a case where shared_hcd is NULL. The other option would be to check for non-null value in hcd and then invoke usb_stop_hcd(). Thanks Kishon