The OPAL RTC driver does not sleep in case it gets OPAL_BUSY or
OPAL_BUSY_EVENT from firmware, which causes large scheduling
latencies, up to 50 seconds have been observed here when RTC stops
responding (BMC reboot can do it).
Fix this by converting it to the standard form OPAL_BUSY loop that
sleeps.
Fixes: 628daa8d5a ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull RTC updates from Alexandre Belloni:
"This contains a few series that have been in preparation for a while
and that will help systems with RTCs that will fail in 2038, 2069 or
2100.
Subsystem:
- Add tracepoints
- Rework of the RTC/nvmem API to allow drivers to discard struct
nvmem_config after registration
- New range API, drivers can now expose the useful range of the RTC
- New offset API the core is now able to add an offset to the RTC
time, modifying the supported range.
- Multiple rtc_time64_to_tm fixes
- Handle time_t overflow on 32 bit platforms in the core instead of
letting drivers do crazy things.
- remove rtc_control API
New driver:
- Intersil ISL12026
Drivers:
- Drivers exposing the RTC non volatile memory have been converted to
use nvmem
- Removed useless time and date validation
- Removed an indirection pattern that was a cargo cult from ancient
drivers
- Removed VLA usage
- Fixed a possible race condition in probe functions
- AB8540 support is dropped from ab8500
- pcf85363 now has alarm support"
* tag 'rtc-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (128 commits)
rtc: snvs: Fix usage of snvs_rtc_enable
rtc: mt7622: fix module autoloading for OF platform drivers
rtc: isl12022: use true and false for boolean values
rtc: ab8500: Drop AB8540 support
rtc: remove a warning during scripts/kernel-doc step
rtc: 88pm860x: remove artificial limitation
rtc: 88pm80x: remove artificial limitation
rtc: st-lpc: remove artificial limitation
rtc: mrst: remove artificial limitation
rtc: mv: remove artificial limitation
rtc: hctosys: Ensure system time doesn't overflow time_t
parisc: time: stop validating rtc_time in .read_time
rtc: pcf85063: fix clearing bits in pcf85063_start_clock
rtc: at91sam9: Set name of regmap_config
rtc: s5m: Remove VLA usage
rtc: s5m: Move enum from rtc.h to rtc-s5m.c
rtc: remove VLA usage
rtc: Add useful timestamp definitions
rtc: Add one offset seconds to expand RTC range
rtc: Factor out the RTC range validation into rtc_valid_range()
...
Pull trivial tree updates from Jiri Kosina.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
kfifo: fix inaccurate comment
tools/thermal: tmon: fix for segfault
net: Spelling s/stucture/structure/
edd: don't spam log if no EDD information is present
Documentation: Fix early-microcode.txt references after file rename
tracing: Block comments should align the * on each line
treewide: Fix typos in printk
GenWQE: Fix a typo in two comments
treewide: Align function definition open/close braces
commit 179a502f8c ("rtc: snvs: add Freescale rtc-snvs driver") introduces
the SNVS RTC driver with a function snvs_rtc_enable().
snvs_rtc_enable() can return an error on the enable path however this
driver does not currently trap that failure on the probe() path and
consequently if enabling the RTC fails we encounter a later error spinning
forever in rtc_write_sync_lp().
[ 36.093481] [<c010d630>] (__irq_svc) from [<c0c2e9ec>] (_raw_spin_unlock_irqrestore+0x34/0x44)
[ 36.102122] [<c0c2e9ec>] (_raw_spin_unlock_irqrestore) from [<c072e32c>] (regmap_read+0x4c/0x5c)
[ 36.110938] [<c072e32c>] (regmap_read) from [<c085d0f4>] (rtc_write_sync_lp+0x6c/0x98)
[ 36.118881] [<c085d0f4>] (rtc_write_sync_lp) from [<c085d160>] (snvs_rtc_alarm_irq_enable+0x40/0x4c)
[ 36.128041] [<c085d160>] (snvs_rtc_alarm_irq_enable) from [<c08567b4>] (rtc_timer_do_work+0xd8/0x1a8)
[ 36.137291] [<c08567b4>] (rtc_timer_do_work) from [<c01441b8>] (process_one_work+0x28c/0x76c)
[ 36.145840] [<c01441b8>] (process_one_work) from [<c01446cc>] (worker_thread+0x34/0x58c)
[ 36.153961] [<c01446cc>] (worker_thread) from [<c014aee4>] (kthread+0x138/0x150)
[ 36.161388] [<c014aee4>] (kthread) from [<c0107e14>] (ret_from_fork+0x14/0x20)
[ 36.168635] rcu_sched kthread starved for 2602 jiffies! g496 c495 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
[ 36.178564] rcu_sched R running task 0 8 2 0x00000000
[ 36.185664] [<c0c288b0>] (__schedule) from [<c0c29134>] (schedule+0x3c/0xa0)
[ 36.192739] [<c0c29134>] (schedule) from [<c0c2db80>] (schedule_timeout+0x78/0x4e0)
[ 36.200422] [<c0c2db80>] (schedule_timeout) from [<c01a7ab0>] (rcu_gp_kthread+0x648/0x1864)
[ 36.208800] [<c01a7ab0>] (rcu_gp_kthread) from [<c014aee4>] (kthread+0x138/0x150)
[ 36.216309] [<c014aee4>] (kthread) from [<c0107e14>] (ret_from_fork+0x14/0x20)
This patch fixes by parsing the result of rtc_write_sync_lp() and
propagating both in the probe and elsewhere. If the RTC doesn't start we
don't proceed loading the driver and don't get into this loop mess later
on.
Fixes: 179a502f8c ("rtc: snvs: add Freescale rtc-snvs driver")
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
It's required to create a modules.alias via MODULE_DEVICE_TABLE helper
for the OF platform driver. Otherwise, module autoloading cannot work.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Assign true or false to boolean variables instead of an integer value.
This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The AB8540 was an evolved version of the AB8500, but it was never
mass produced or put into products, only reference designs exist.
The upstream support was never completed and it is unlikely that
this will happen so drop the support for now to simplify
maintenance of the AB8500.
Cc: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
During compilation using W=1 one would get:
drivers/rtc/systohc.c:11: info: Scanning doc for rtc_set_ntp_time
drivers/rtc/systohc.c:23: warning: bad line: (
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The 88pm860x supports time up to 2106 (it is a 32 bit counter). Also, the
year will never be before 1970 as the RTC core forbids that.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The 88pm80x supports time up to 2106 (it is a 32 bit counter). Also, the
year will never be before 1970 as the RTC core forbids that.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The LPC RTC supports dates way beyond 2038, don't limit it artificially as
the kernel handles dates after 2038 properly.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Dates after 2038 actually fit on 32 bits. The counter will overflow in
2106. Also, it is bad practice to reset the RTC to a default value.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
On 32bit platforms, time_t is still a signed 32bit long. If it is
overflowed, userspace and the kernel cant agree on the current system time.
This causes multiple issues, in particular with systemd:
https://github.com/systemd/systemd/issues/1143
A good workaround is to simply avoid using hctosys which is something I
greatly encourage as the time is better set by userspace.
However, many distribution enable it and use systemd which is rendering the
system unusable in case the RTC holds a date after 2038 (and more so after
2106). Many drivers have workaround for this case and they should be
eliminated so there is only one place left to fix when userspace is able to
cope with dates after the 31bit overflow.
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The tile architecture is getting removed, so this driver is
no longer needed.
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
A lot of Kconfig symbols have architecture specific dependencies.
In those cases that depend on architectures we have already removed,
they can be omitted.
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
We are now allowing to register debugfs without a valid device, and not
having a valid name will end up using "dummy*" to create debugfs dir.
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
In preparation to enabling -Wvla, remove VLAs and replace them
with fixed-length arrays instead.
>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.
Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
In preparation to enabling -Wvla, remove VLA and replace it
with a fixed-length array instead.
>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.
Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
From our investigation for all RTC drivers, 1 driver will be expired before
year 2017, 7 drivers will be expired before year 2038, 23 drivers will be
expired before year 2069, 72 drivers will be expired before 2100 and 104
drivers will be expired before 2106. Especially for these early expired
drivers, we need to expand the RTC range to make the RTC can still work
after the expired year.
So we can expand the RTC range by adding one offset to the time when reading
from hardware, and subtracting it when writing back. For example, if you have
an RTC that can do 100 years, and currently is configured to be based in
Jan 1 1970, so it can represents times from 1970 to 2069. Then if you change
the start year from 1970 to 2000, which means it can represents times from
2000 to 2099. By adding or subtracting the offset produced by moving the wrap
point, all times between 1970 and 1999 from RTC hardware could get interpreted
as times from 2070 to 2099, but the interpretation of dates between 2000 and
2069 would not change.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
The RTC range validation code can be factored into rtc_valid_range()
function to avoid duplicate code.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
