| Message ID | 1410430179-19944-1-git-send-email-sanjeev_sharma@mentor.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Thu, 2014-09-11 at 15:39 +0530, Sanjeev Sharma wrote: > 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@mentor.com> > --- > Changes in v2: > - corrected the typo Now it compiles, but you got the logic wrong. > +++ b/drivers/net/wireless/zd1211rw/zd_mac.c > @@ -235,7 +235,7 @@ void zd_mac_clear(struct zd_mac *mac) > { > flush_workqueue(zd_workqueue); > zd_chip_clear(&mac->chip); > - ZD_ASSERT(!spin_is_locked(&mac->lock)); > + lockdep_assert_held(&mac->lock); > ZD_MEMCLEAR(mac, sizeof(struct zd_mac)); > } Look closely at this again. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-----Original Message----- From: Johannes Berg [mailto:johannes@sipsolutions.net] Sent: Thursday, September 11, 2014 3:42 PM To: Sharma, Sanjeev Cc: dsd@gentoo.org; kune@deine-taler.de; linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org Subject: Re: [PATCH v2] zd1211rw: replace ZD_ASSERT with lockdep_assert_held() On Thu, 2014-09-11 at 15:39 +0530, Sanjeev Sharma wrote: > 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@mentor.com> > --- > Changes in v2: > - corrected the typo > Now it compiles, but you got the logic wrong. > +++ b/drivers/net/wireless/zd1211rw/zd_mac.c > @@ -235,7 +235,7 @@ void zd_mac_clear(struct zd_mac *mac) { > flush_workqueue(zd_workqueue); > zd_chip_clear(&mac->chip); > - ZD_ASSERT(!spin_is_locked(&mac->lock)); > + lockdep_assert_held(&mac->lock); > ZD_MEMCLEAR(mac, sizeof(struct zd_mac)); } >Look closely at this again. I didn't understand where I put wrong logic ? Regards Sanjeev Sharma
On Thu, 2014-09-11 at 10:36 +0000, Sharma, Sanjeev wrote: > > - ZD_ASSERT(!spin_is_locked(&mac->lock)); > > + lockdep_assert_held(&mac->lock); > >Look closely at this again. > > I didn't understand where I put wrong logic ? Ok, that's fine. But please send a new patch only when you've understood the logic. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Sanjeev, On Thu, Sep 11, 2014 at 8:36 PM, Sharma, Sanjeev <Sanjeev_Sharma@mentor.com> wrote: > -----Original Message----- > From: Johannes Berg [mailto:johannes@sipsolutions.net] > Sent: Thursday, September 11, 2014 3:42 PM > To: Sharma, Sanjeev > Cc: dsd@gentoo.org; kune@deine-taler.de; linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org > Subject: Re: [PATCH v2] zd1211rw: replace ZD_ASSERT with lockdep_assert_held() > > On Thu, 2014-09-11 at 15:39 +0530, Sanjeev Sharma wrote: >> 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@mentor.com> >> --- >> Changes in v2: >> - corrected the typo > >> Now it compiles, but you got the logic wrong. > >> +++ b/drivers/net/wireless/zd1211rw/zd_mac.c >> @@ -235,7 +235,7 @@ void zd_mac_clear(struct zd_mac *mac) { >> flush_workqueue(zd_workqueue); >> zd_chip_clear(&mac->chip); >> - ZD_ASSERT(!spin_is_locked(&mac->lock)); >> + lockdep_assert_held(&mac->lock); >> ZD_MEMCLEAR(mac, sizeof(struct zd_mac)); } > >>Look closely at this again. > > I didn't understand where I put wrong logic ? I find it helps to spell out what code is doing in words. E.g. the line you're removing is: ZD_ASSERT(!spin_is_locked(&mac->lock)); So, we'll assert when spin_is_locked(&mac->lock) is false, i.e. when mac->lock is not spin locked. This isn't the same as what you're replacing it with. Thanks,
-----Original Message----- From: Julian Calaby [mailto:julian.calaby@gmail.com] Sent: Monday, September 15, 2014 11:32 AM To: Sharma, Sanjeev Cc: Johannes Berg; dsd@gentoo.org; kune@deine-taler.de; linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org Subject: Re: [PATCH v2] zd1211rw: replace ZD_ASSERT with lockdep_assert_held() Hi Sanjeev, On Thu, Sep 11, 2014 at 8:36 PM, Sharma, Sanjeev <Sanjeev_Sharma@mentor.com> wrote: > -----Original Message----- > From: Johannes Berg [mailto:johannes@sipsolutions.net] > Sent: Thursday, September 11, 2014 3:42 PM > To: Sharma, Sanjeev > Cc: dsd@gentoo.org; kune@deine-taler.de; > linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; > netdev@vger.kernel.org > Subject: Re: [PATCH v2] zd1211rw: replace ZD_ASSERT with > lockdep_assert_held() > > On Thu, 2014-09-11 at 15:39 +0530, Sanjeev Sharma wrote: >> 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@mentor.com> >> --- >> Changes in v2: >> - corrected the typo > >> Now it compiles, but you got the logic wrong. > >> +++ b/drivers/net/wireless/zd1211rw/zd_mac.c >> @@ -235,7 +235,7 @@ void zd_mac_clear(struct zd_mac *mac) { >> flush_workqueue(zd_workqueue); >> zd_chip_clear(&mac->chip); >> - ZD_ASSERT(!spin_is_locked(&mac->lock)); >> + lockdep_assert_held(&mac->lock); >> ZD_MEMCLEAR(mac, sizeof(struct zd_mac)); } > >>Look closely at this again. > > I didn't understand where I put wrong logic ? I find it helps to spell out what code is doing in words. E.g. the line you're removing is: ZD_ASSERT(!spin_is_locked(&mac->lock)); So, we'll assert when spin_is_locked(&mac->lock) is false, i.e. when mac->lock is not spin locked. This isn't the same as what you're replacing it with. I feel logic is absolutely correct and if you expand it will looks like .. +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && !lockdep_is_held(l)); \ + } while (0) Please refer http://lkml.iu.edu/hypermail/linux/kernel/1203.2/00369.html and also see include/linux/lockdep.h for more detail. Thanks Sanjeev Sharma
diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c index e7af261..adce2ee 100644 --- a/drivers/net/wireless/zd1211rw/zd_mac.c +++ b/drivers/net/wireless/zd1211rw/zd_mac.c @@ -235,7 +235,7 @@ void zd_mac_clear(struct zd_mac *mac) { flush_workqueue(zd_workqueue); zd_chip_clear(&mac->chip); - ZD_ASSERT(!spin_is_locked(&mac->lock)); + lockdep_assert_held(&mac->lock); ZD_MEMCLEAR(mac, sizeof(struct zd_mac)); }
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@mentor.com> --- Changes in v2: - corrected the typo drivers/net/wireless/zd1211rw/zd_mac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)