-----Original Message----- From: Hans de Goede [mailto:hdegoede@xxxxxxxxxx] Sent: Wednesday, September 10, 2014 8:33 PM To: Peter Hurley; Greg Kroah-Hartman Cc: linux-usb@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; Sharma, Sanjeev; Peter Zijlstra; Ingo Molnar Subject: Re: [PATCH 01/21] uas: replace WARN_ON_ONCE() with lockdep_assert_held() Hi, On 09/10/2014 04:38 PM, Peter Hurley wrote: > [ +cc Peter Zijlstra, Ingo Molnar ] > > On 09/10/2014 07:46 AM, Hans de Goede wrote: >> From: Sanjeev Sharma <Sanjeev_Sharma@xxxxxxxxxx> >> >> On some architecture spin_is_locked() always return false in >> uniprocessor configuration and therefore it would be advise to >> replace with lockdep_assert_held(). >> >> Signed-off-by: Sanjeev Sharma <Sanjeev_Sharma@xxxxxxxxxx> >> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> >> --- >> drivers/usb/storage/uas.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c >> index 3f42785..05b2d8e 100644 >> --- a/drivers/usb/storage/uas.c >> +++ b/drivers/usb/storage/uas.c >> @@ -154,7 +154,7 @@ static void uas_mark_cmd_dead(struct uas_dev_info *devinfo, >> struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp); >> >> uas_log_cmd_state(cmnd, caller); >> - WARN_ON_ONCE(!spin_is_locked(&devinfo->lock)); >> + lockdep_assert_held(&devinfo->lock); > > This change isn't equivalent. > > lockdep_assert_held() will continue to emit warnings; ie., there is no > "once" functionality. Same for the other changes below. >Given that these should really never ever happen, that is not really a problem IMHO. The idea ws to replace the wrong use of spin_is_locked with some other sanity check, preferably a light weight one, the once behavior is not that important. I am totally agree with the hans and that was my intention for UP system. Regards Sanjeev Sharma ��.n��������+%������w��{.n�����������ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f