| Message ID | 1385415876-12387-7-git-send-email-joelf@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Joel Fernandes <joelf@ti.com> [131125 13:46]: > Enabling of Posted mode is seen to cause problems on dmtimer modules on AM33xx > (much like other OMAPs). Reference discussions on forums [1] [2]. Earlier > patch solving this on other OMAPs [3]. > > For OMAP SoCs with this errata, the fix has been to not enable Posted mode. > However, on some SoCs (atleast AM33xx) which carry this errata, Posted mode > is enabled on reset. So we not only need to ignore enabling of the POSTED bit > when the timer is requested, but also disable Posted mode if errata is present. This could explain some occasional lost timers I saw a while back when testing things.. We most likely should merge for the -rc series with cc stable. Does this depend on the other patches in this series? Regards, Tony > [1] http://e2e.ti.com/support/arm/sitara_arm/f/791/t/285744.aspx > [2] http://e2e.ti.com/support/arm/sitara_arm/f/791/t/270632.aspx > [3] http://www.spinics.net/lists/linux-omap/msg81770.html > > Reported-by: Russ Dill <russ.dill@ti.com> > Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> > Signed-off-by: Joel Fernandes <joelf@ti.com> > --- > arch/arm/plat-omap/include/plat/dmtimer.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h > index fb92abb..2861b15 100644 > --- a/arch/arm/plat-omap/include/plat/dmtimer.h > +++ b/arch/arm/plat-omap/include/plat/dmtimer.h > @@ -336,8 +336,11 @@ static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer) > if (timer->posted) > return; > > - if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) > + if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) { > + timer->posted = OMAP_TIMER_NONPOSTED; > + __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0, 0); > return; > + } > > __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, > OMAP_TIMER_CTRL_POSTED, 0); > -- > 1.8.1.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/25/2013 04:14 PM, Tony Lindgren wrote: > * Joel Fernandes <joelf@ti.com> [131125 13:46]: >> Enabling of Posted mode is seen to cause problems on dmtimer modules on AM33xx >> (much like other OMAPs). Reference discussions on forums [1] [2]. Earlier >> patch solving this on other OMAPs [3]. >> >> For OMAP SoCs with this errata, the fix has been to not enable Posted mode. >> However, on some SoCs (atleast AM33xx) which carry this errata, Posted mode >> is enabled on reset. So we not only need to ignore enabling of the POSTED bit >> when the timer is requested, but also disable Posted mode if errata is present. > > This could explain some occasional lost timers I saw a while back when > testing things.. We most likely should merge for the -rc series with cc stable. Sure, I agree. > > Does this depend on the other patches in this series? > No it doesn't depend. thanks, -Joel -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Joel Fernandes <joelf@ti.com> [131125 14:18]: > On 11/25/2013 04:14 PM, Tony Lindgren wrote: > > * Joel Fernandes <joelf@ti.com> [131125 13:46]: > >> Enabling of Posted mode is seen to cause problems on dmtimer modules on AM33xx > >> (much like other OMAPs). Reference discussions on forums [1] [2]. Earlier > >> patch solving this on other OMAPs [3]. > >> > >> For OMAP SoCs with this errata, the fix has been to not enable Posted mode. > >> However, on some SoCs (atleast AM33xx) which carry this errata, Posted mode > >> is enabled on reset. So we not only need to ignore enabling of the POSTED bit > >> when the timer is requested, but also disable Posted mode if errata is present. > > > > This could explain some occasional lost timers I saw a while back when > > testing things.. We most likely should merge for the -rc series with cc stable. > > Sure, I agree. > > > > > Does this depend on the other patches in this series? > > > > No it doesn't depend. OK thanks applying into omap-for-v3.13/fixes-take4. Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat-omap/include/plat/dmtimer.h index fb92abb..2861b15 100644 --- a/arch/arm/plat-omap/include/plat/dmtimer.h +++ b/arch/arm/plat-omap/include/plat/dmtimer.h @@ -336,8 +336,11 @@ static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer) if (timer->posted) return; - if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) + if (timer->errata & OMAP_TIMER_ERRATA_I103_I767) { + timer->posted = OMAP_TIMER_NONPOSTED; + __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, 0, 0); return; + } __omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG, OMAP_TIMER_CTRL_POSTED, 0);
Enabling of Posted mode is seen to cause problems on dmtimer modules on AM33xx (much like other OMAPs). Reference discussions on forums [1] [2]. Earlier patch solving this on other OMAPs [3]. For OMAP SoCs with this errata, the fix has been to not enable Posted mode. However, on some SoCs (atleast AM33xx) which carry this errata, Posted mode is enabled on reset. So we not only need to ignore enabling of the POSTED bit when the timer is requested, but also disable Posted mode if errata is present. [1] http://e2e.ti.com/support/arm/sitara_arm/f/791/t/285744.aspx [2] http://e2e.ti.com/support/arm/sitara_arm/f/791/t/270632.aspx [3] http://www.spinics.net/lists/linux-omap/msg81770.html Reported-by: Russ Dill <russ.dill@ti.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Joel Fernandes <joelf@ti.com> --- arch/arm/plat-omap/include/plat/dmtimer.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)