| Message ID | 1323730073.4078.97.camel@work-vm |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, 12 Dec 2011 14:47:53 -0800 John Stultz <john.stultz@linaro.org> wrote: > On Sun, 2011-12-04 at 03:29 +0100, acrux_it@libero.it wrote: > > Acube Sam460ex is a 460ex SoC (PowerPC) based board with m41t81 > > like RTC. The wrong beahviour it seems to be caused this commit: > > > > Thu, 3 Feb 2011 21:02:35 +0000 (13:02 -0800) > > commit 16380c153a69c3784d2afaddfe0a22f353046cf6 > > RTC: Convert rtc drivers to use the alarm_irq_enable method > > http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commit; > > h=16380c153a69c3784d2afaddfe0a22f353046cf6 > > Yea. This was reported earlier, but it seems none of the proposed > solutions have been implemented. > > The cause is that the m41t80 driver's alarm functionality is somehow > broken. The alarm mode is actually now used for UIE, so where before > 2.6.38, UIE mode returned -EINVAL, it will now succeed, setting the > alarm to fire a second away. > > However, since the alarm code is broken, no alarm arrives and you get > the timeout you see. > > Could you test the following patch to see if it resolves the issue for > you? If it does, I'll queue it for inclusion. > > thanks > -john > hallo John, CC to linuxppc-dev@lists.ozlabs.org thanks for your time, this escamotage works fine. I tested your patch against linux-2.6.38.8 and linux-3.1.5. Tested-by: Nico Macrionitis <acrux@cruxppc.org> cheers, Nico > > [PATCH] rtc: m41t80: Workaround broken alarm functionality > > The m41t80 driver doesn't seem to have a functional alarm. > > This causes failures when the generic core sees alarm functions, > but then cannot use them properly for things like UIE mode. > > Disabling the alarm functions allows proper error reporting, > and possible fallback to emulated modes. Once someone fixes > the alarm functions, this can be restored. > > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > drivers/rtc/rtc-m41t80.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c > index eda128f..64aedd8 100644 > --- a/drivers/rtc/rtc-m41t80.c > +++ b/drivers/rtc/rtc-m41t80.c > @@ -357,10 +357,19 @@ static int m41t80_rtc_read_alarm(struct device > *dev, struct rtc_wkalrm *t) static struct rtc_class_ops > m41t80_rtc_ops = { .read_time = m41t80_rtc_read_time, > .set_time = m41t80_rtc_set_time, > + /* > + * XXX - m41t80 alarm functionality is reported broken. > + * until it is fixed, don't register alarm functions. > + * > .read_alarm = m41t80_rtc_read_alarm, > .set_alarm = m41t80_rtc_set_alarm, > + */ > .proc = m41t80_rtc_proc, > + /* > + * See above comment on broken alarm > + * > .alarm_irq_enable = m41t80_rtc_alarm_irq_enable, > + */ > }; > > #if defined(CONFIG_RTC_INTF_SYSFS) || defined > #(CONFIG_RTC_INTF_SYSFS_MODULE) > -- > 1.7.3.2.146.gca209 > > >
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c index eda128f..64aedd8 100644 --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -357,10 +357,19 @@ static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t) static struct rtc_class_ops m41t80_rtc_ops = { .read_time = m41t80_rtc_read_time, .set_time = m41t80_rtc_set_time, + /* + * XXX - m41t80 alarm functionality is reported broken. + * until it is fixed, don't register alarm functions. + * .read_alarm = m41t80_rtc_read_alarm, .set_alarm = m41t80_rtc_set_alarm, + */ .proc = m41t80_rtc_proc, + /* + * See above comment on broken alarm + * .alarm_irq_enable = m41t80_rtc_alarm_irq_enable, + */ }; #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)