linux/drivers/rtc/rtc-dev.c, branch v2.6.25

rtc-cmos alarm acts as oneshot

2008-02-06T18:41:13Z

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 Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

RTC: assure proper memory ordering with respect to RTC_DEV_BUSY flag

2007-12-05T17:21:18Z

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 Cc: Nick Piggin Cc: David Brownell Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

RTC: convert mutex to bitfield

2007-11-29T17:24:54Z

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 Acked-by: Alessandro Zummo Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc: allow validated RTC_PIE_ON for non-root

2007-10-16T16:43:13Z

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 Acked-by: Alessandro Zummo Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc-dev: no need to convert file->private_data to rtc device

2007-10-16T16:43:13Z

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 Signed-off-by: Mark Zhan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

RTC: periodic irq fix

2007-10-16T16:43:13Z

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 Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc-dev: Make RTC driver return ENOTTY instead of ENOIOCTLCMD

2007-07-31T22:39:36Z

Prevent the RTC driver from returning ENOIOCTLCMD to userspace. Signed-off-by: Thomas Hommel Acked-by: Alessandro Zummo Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc-dev: return -ENOTTY in ioctl if irq_set_freq is not implemented by driver

2007-07-17T17:23:09Z

Signed-off-by: Hans-Christian Egtvedt Cc: Haavard Skinnemoen Cc: David Brownell Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc: remove "RTC_ALM_SET mode" bugs

2007-05-08T18:15:19Z

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 Cc: Scott Wood Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc: update to class device removal patches

2007-05-08T18:15:18Z

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 Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds