With commit 5ad31a5751 ("rtc: remove BKL
for ioctl()"), RTC_UIE_ON ioctl cause double lock on rtc->ops_lock.
The ops_lock must not be held while set_uie() calls rtc_read_time()
which takes the lock. Also clear_uie() does not need ops_lock. This
patch fixes return value of RTC_UIE_OFF ioctl too.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert commit 51a776fa7a ("rtc: cdev
lock_kernel() pushdown"). The RTC framework does not need BKL
protection.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Solves http://bugzilla.kernel.org/show_bug.cgi?id=11127
The old rtc.c driver did it and some drivers (like rtc-sh) do it in their
release function, though they should not -- because they should provide
the irq_set_state op and the rtc framework itself should care about it.
This patch makes it do so.
I am aware that some drivers, like rtc-sh, handle userspace PIE sets in
their ioctl op (instead of having the framework call the op), exporting
the irq_set_state op at the same time. The logic in rtc_irq_set_state
should make sure it doesn't matter and the driver should not need to care
stopping periodic interrupts in its release routine any more.
The correct way, in my opinion, should be this:
1) The driver provides the irq_set_state op and does not care closing the
interrupts in its release op.
2) If the driver does not provide the op and handles PIE in the ioctl op, it's
reponsible for closing them in its release op.
3) Something similar for other IRQs, like UIE -- if there's no in-kernel API
like irq_set_state, handle it in ioctl and release ops. The framework will
be responsible either for everything or for nothing. (This will probably
change later.)
Signed-off-by: Tomas Janousek <tomi@nomi.cz>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was pointed out that the RTC framework handles its mutex locks oddly
... returning -EBUSY when interrupted. This fixes that by returning the
value of mutex_lock_interruptible() (i.e. -EINTR).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove implicit use of BKL in ioctl() from the RTC framework.
Instead, the rtc->ops_lock is used. That's the same lock that already
protects the RTC operations when they're issued through the exported
rtc_*() calls in drivers/rtc/interface.c ... making this a bugfix, not
just a cleanup, since both ioctl calls and set_alarm() need to update IRQ
enable flags and that implies a common lock (which RTC drivers as a rule
do not provide on their own).
A new comment at the declaration of "struct rtc_class_ops" summarizes
current locking rules. It's not clear to me that the exceptions listed
there should exist ... if not, those are pre-existing problems which can
be fixed in a patch that doesn't relate to BKL removal.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Start making the rtc-cmos alarm act more like a oneshot alarm by disabling
that alarm after its IRQ fires. (ACPI hooks are also needed.)
The Linux RTC framework has previously been a bit vague in this area, but
any other behavior is problematic and not very portable. RTCs with full
YYYY-MM-DD HH:MM[:SS] alarms won't have a problem here. Only ones with
partial match criteria, with the most visible example being the PC RTC, get
confused. (Because the criteria will match repeatedly.)
Update comments relating to that oneshot behavior and timezone handling.
(Timezones are another issue that's mostly visible with rtc-cmos. That's
because PCs often dual-boot MS-Windows, which likes its RTC to match local
wall-clock time instead of UTC.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We must make sure that the RTC_DEV_BUSY flag has proper lock semantics,
i.e. that the RTC_DEV_BUSY stores clearing the flag don't get reordered
before the preceeding stores and loads and vice versa.
Spotted by Nick Piggin.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RTC code is using mutex to assure exclusive access to /dev/rtc. This is
however wrong usage, as it leaves the mutex locked when returning into
userspace, which is unacceptable.
Convert rtc->char_lock into bit operation.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/char/rtc.c allowed RTC_PIE_ON ioctls for non-root users, as long as
the current interval (set via RTC_IRQP_SET) is <= max_user_freq. Allow
RTC_PIE_ON under the same conditions when /dev/rtc* is handled by the rtc
subsystem.
Signed-off-by: Bryan Kadzban <bryan@kdzbn.homelinux.net>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In rtc-dev.c, when a rtc device is opened, file->private_data is already
attached with the rtc device pointer, so there is no need to call
to_rtc_device() to convert file->private_data to a rtc device pointer.
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Mark Zhan <rongkai.zhan@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add kernel/kernel and kernel/user locking for the periodic irq feature of
the rtc class.
PIE ioctls are also supported.
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prevent the RTC driver from returning ENOIOCTLCMD to userspace.
Signed-off-by: Thomas Hommel <thomas.hommel@gefanuc.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a common glitch in how RTC drivers handle two "set alarm" modes,
by getting rid of the surprising/hidden one that was rarely implemented
correctly (and which could expose nonportable hardware-specific behavior).
The glitch comes from the /dev/rtcX logic implementing the legacy
RTC_ALM_SET (limited to 24 hours, needing RTC_AIE_ON) ioctl on top of the
RTC driver call providing access to the newer RTC_WKALM_SET (without those
limitations) by initializing the day/month/year fields to be invalid ...
that second mode.
Now, since few RTC drivers check those fields, and most hardware misbehaves
when faced with invalid date fields, many RTC drivers will set bogus alarm
times on those RTC_ALM_SET code paths. (Several in-tree drivers have that
issue, and I also noticed it with code reviews on several new RTC drivers.)
This patch ensures that RTC drivers never see such invalid alarm fields, by
moving some logic out of rtc-omap into the RTC_ALM_SET code and adding an
explicit check (which will prevent the issue on other code paths).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a goof in the revised classdev support for RTCs: make sure the /dev
node info is ready before the device is registered, not after. Otherwise
the /sys/class/rtc/rtcN/dev attribute won't be created and then udev won't
have the information it needs to create the /dev/rtcN node.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes class_device from the programming interface that the RTC
framework exposes to the rest of the kernel. Now an rtc_device is passed,
which is more type-safe and streamlines all the relevant code.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This simplifies the /dev support by removing a superfluous class_device (the
/sys/class/rtc-dev stuff) and the class_interface that hooks it into the rtc
core. Accordingly, if it's configured then /dev support is now part of the
RTC core, and is never a separate module.
It's another step towards being able to remove "struct class_device".
[bunk@stusta.de: drivers/rtc/rtc-dev.c should #include "rtc-core.h"]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-By: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes some syslog spam as RTC drivers register; debug messages
shouldn't come out at "info" level.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Conflicts:
drivers/infiniband/core/iwcm.c
drivers/net/chelsio/cxgb2.c
drivers/net/wireless/bcm43xx/bcm43xx_main.c
drivers/net/wireless/prism54/islpci_eth.c
drivers/usb/core/hub.h
drivers/usb/input/hid-core.c
net/core/netpoll.c
Fix up merge failures with Linus's head and fix new compilation failures.
Signed-Off-By: David Howells <dhowells@redhat.com>
I got a lockdep warning when running "rtctest" so I though it'd be good
to see what was up.
- The warning was for rtc->irq_task_lock, gotten from rtc_update_irq()
by irq handlerss ... but in a handful of other cases, grabbed without
blocking IRQs.
- Some callers to rtc_update_irq() were not ensuring IRQs were blocked,
yet the routine expects that; make sure all callers block IRQs.
It would appear that RTC API tests haven't been part of anyone's kernel
regression test suite recently, at least not with lockdep running.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The RTC framework has an irq_set_freq() method that should be used to manage
the periodic IRQ frequency, but the current ioctl logic doesn't know how to do
that. This patch teaches it how.
This means that drivers implementing irq_set_freq() will automatically support
RTC_IRQP_{READ,SET} ioctls; that logic doesn't need duplication within the
driver.
[akpm@osdl.org: export rtc_irq_set_freq]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update RTC framework so that drivers can constify their method tables, moving
them from ".data" to ".rodata". Then update the drivers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes RTC core components use "subsys_init" instead of "module_init", as
appropriate for subsystem infrastructure. This is mostly useful for
statically linking drivers in other parts of the tree that may provide an RTC
interface as a secondary functionality (e.g. part of a multifunction chip);
they won't need to worry so much about drivers/Makefile link order.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Oleg Verych <olecom@flower.upol.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If cdev_add() fails there is no good reason to call cdev_del().
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver with
slight adjustments/refinements. This makes UIE-less rtc drivers work
better with programs doing read/poll on /dev/rtc, such as hwclock. This
emulation should not harm rtc drivers with UIE support, since
rtc_dev_ioctl() calls underlaying rtc driver's ioctl() first.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Appropriately use -ENOIOCTLCMD and -ENOTTY when the ioctl is not
implemented by a driver.
(akpm: we're not allowed to return -ENOIOCTLCMD to userspace. This patch does
the right thing).
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make rtc-dev work well on 64-bit platforms with 32-bit userland. On those
platforms, users might try to read 32-bit integer value. This patch make
rtc-dev's read() work well for both "int" and "long" size. This tweak is came
from genrtc driver.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add the dev interface to the RTC subsystem.
Each RTC will be available under /dev/rtcX . A symlink from /dev/rtc0 to
/dev/rtc cab be obtained with the following udev rule:
KERNEL=="rtc0", SYMLINK+="rtc"
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
