- 23 Mar, 2012 40 commits
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KAMEZAWA Hiroyuki authored
Process accounting applications as top, ps visit some files under /proc/<pid>. With seq_put_decimal_ull(), we can optimize /proc/<pid>/stat and /proc/<pid>/statm files. This patch adds - seq_put_decimal_ll() for signed values. - allow delimiter == 0. - convert seq_printf() to seq_put_decimal_ull/ll in /proc/stat, statm. Test result on a system with 2000+ procs. Before patch: [kamezawa@bluextal test]$ top -b -n 1 | wc -l 2223 [kamezawa@bluextal test]$ time top -b -n 1 > /dev/null real 0m0.675s user 0m0.044s sys 0m0.121s [kamezawa@bluextal test]$ time ps -elf > /dev/null real 0m0.236s user 0m0.056s sys 0m0.176s After patch: kamezawa@bluextal ~]$ time top -b -n 1 > /dev/null real 0m0.657s user 0m0.052s sys 0m0.100s [kamezawa@bluextal ~]$ time ps -elf > /dev/null real 0m0.198s user 0m0.050s sys 0m0.145s Considering top, ps tend to scan /proc periodically, this will reduce cpu consumption by top/ps to some extent. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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KAMEZAWA Hiroyuki authored
== stat_check.py num = 0 with open("/proc/stat") as f: while num < 1000 : data = f.read() f.seek(0, 0) num = num + 1 == perf shows 20.39% stat_check.py [kernel.kallsyms] [k] format_decode 13.41% stat_check.py [kernel.kallsyms] [k] number 12.61% stat_check.py [kernel.kallsyms] [k] vsnprintf 10.85% stat_check.py [kernel.kallsyms] [k] memcpy 4.85% stat_check.py [kernel.kallsyms] [k] radix_tree_lookup 4.43% stat_check.py [kernel.kallsyms] [k] seq_printf This patch removes most of calls to vsnprintf() by adding num_to_str() and seq_print_decimal_ull(), which prints decimal numbers without rich functions provided by printf(). On my 8cpu box. == Before patch == [root@bluextal test]# time ./stat_check.py real 0m0.150s user 0m0.026s sys 0m0.121s == After patch == [root@bluextal test]# time ./stat_check.py real 0m0.055s user 0m0.022s sys 0m0.030s [akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()] [andrea@betterlinux.com: avoid breaking the ABI in /proc/stat] Signed-off-by:Andrea Righi <andrea@betterlinux.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Turner <pjt@google.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by:
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Eric Dumazet authored
On a typical 16 cpus machine, "cat /proc/stat" gives more than 4096 bytes, and is slow : # strace -T -o /tmp/STRACE cat /proc/stat | wc -c 5826 # grep "cpu " /tmp/STRACE read(0, "cpu 1949310 19 2144714 12117253"..., 32768) = 5826 <0.001504> Thats partly because show_stat() must be called twice since initial buffer size is too small (4096 bytes for less than 32 possible cpus) Fix this by : 1) Taking into account nr_irqs in the initial buffer sizing. 2) Using ksize() to allow better filling of initial buffer. Signed-off-by:
Eric Dumazet <eric.dumazet@gmail.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Djalal Harouni authored
get_sparsemem_vmemmap_info() is only used inside fs/proc/kcore.c Signed-off-by:
Djalal Harouni <tixxdz@opendz.org> Reviewed-by:
WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by:
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Jason Baron authored
Since we no longer need the VM_ALWAYSDUMP flag, let's use the freed bit for 'VM_NODUMP' flag. The idea is is to add a new madvise() flag: MADV_DONTDUMP, which can be set by applications to specifically request memory regions which should not dump core. The specific application I have in mind is qemu: we can add a flag there that wouldn't dump all of guest memory when qemu dumps core. This flag might also be useful for security sensitive apps that want to absolutely make sure that parts of memory are not dumped. To clear the flag use: MADV_DODUMP. [akpm@linux-foundation.org: s/MADV_NODUMP/MADV_DONTDUMP/, s/MADV_CLEAR_NODUMP/MADV_DODUMP/, per Roland] [akpm@linux-foundation.org: fix up the architectures which broke] Signed-off-by:
Jason Baron <jbaron@redhat.com> Acked-by:
Roland McGrath <roland@hack.frob.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Avi Kivity <avi@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Signed-off-by:
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Jason Baron authored
The motivation for this patchset was that I was looking at a way for a qemu-kvm process, to exclude the guest memory from its core dump, which can be quite large. There are already a number of filter flags in /proc/<pid>/coredump_filter, however, these allow one to specify 'types' of kernel memory, not specific address ranges (which is needed in this case). Since there are no more vma flags available, the first patch eliminates the need for the 'VM_ALWAYSDUMP' flag. The flag is used internally by the kernel to mark vdso and vsyscall pages. However, it is simple enough to check if a vma covers a vdso or vsyscall page without the need for this flag. The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new 'VM_NODUMP' flag, which can be set by userspace using new madvise flags: 'MADV_DONTDUMP', and unset via 'MADV_DODUMP'. The core dump filters continue to work the same as before unless 'MADV_DONTDUMP' is set on the region. The qemu code which implements this features is at: http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch In my testing the qemu core dump shrunk from 383MB -> 13MB with this patch. I also believe that the 'MADV_DONTDUMP' flag might be useful for security sensitive apps, which might want to select which areas are dumped. This patch: The VM_ALWAYSDUMP flag is currently used by the coredump code to indicate that a vma is part of a vsyscall or vdso section. However, we can determine if a vma is in one these sections by checking it against the gate_vma and checking for a non-NULL return value from arch_vma_name(). Thus, freeing a valuable vma bit. Signed-off-by:
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Oleg Nesterov authored
As Tetsuo Handa pointed out, request_module() can stress the system while the oom-killed caller sleeps in TASK_UNINTERRUPTIBLE. The task T uses "almost all" memory, then it does something which triggers request_module(). Say, it can simply call sys_socket(). This in turn needs more memory and leads to OOM. oom-killer correctly chooses T and kills it, but this can't help because it sleeps in TASK_UNINTERRUPTIBLE and after that oom-killer becomes "disabled" by the TIF_MEMDIE task T. Make __request_module() killable. The only necessary change is that call_modprobe() should kmalloc argv and module_name, they can't live in the stack if we use UMH_KILLABLE. This memory is freed via call_usermodehelper_freeinfo()->cleanup. Reported-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
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Oleg Nesterov authored
No functional changes. Move the call_usermodehelper code from __request_module() into the new simple helper, call_modprobe(). Signed-off-by:
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Oleg Nesterov authored
Minor cleanup. ____call_usermodehelper() can simply return, no need to call do_exit() explicitely. Signed-off-by:
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Oleg Nesterov authored
No functional changes. It is not sane to use UMH_KILLABLE with enum umh_wait, but obviously we do not want another argument in call_usermodehelper_* helpers. Kill this enum, use the plain int. Signed-off-by:
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Oleg Nesterov authored
Implement UMH_KILLABLE, should be used along with UMH_WAIT_EXEC/PROC. The caller must ensure that subprocess_info->path/etc can not go away until call_usermodehelper_freeinfo(). call_usermodehelper_exec(UMH_KILLABLE) does wait_for_completion_killable. If it fails, it uses xchg(&sub_info->complete, NULL) to serialize with umh_complete() which does the same xhcg() to access sub_info->complete. If call_usermodehelper_exec wins, it can safely return. umh_complete() should get NULL and call call_usermodehelper_freeinfo(). Otherwise we know that umh_complete() was already called, in this case call_usermodehelper_exec() falls back to wait_for_completion() which should succeed "very soon". Note: UMH_NO_WAIT == -1 but it obviously should not be used with UMH_KILLABLE. We delay the neccessary cleanup to simplify the back porting. Signed-off-by:
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Oleg Nesterov authored
Preparation. Add the new trivial helper, umh_complete(). Currently it simply does complete(sub_info->complete). Signed-off-by:
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Oleg Nesterov authored
A few call_usermodehelper() callers use the hardcoded constant instead of the proper UMH_WAIT_PROC, fix them. Reported-by:
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Oleg Nesterov authored
Change zap_pid_ns_processes() to use SEND_SIG_FORCED, it looks more clear compared to SEND_SIG_NOINFO which relies on from_ancestor_ns logic send_signal(). It is also more efficient if we need to kill a lot of tasks because it doesn't alloc sigqueue. While at it, add the __fatal_signal_pending(task) check as a minor optimization. Signed-off-by:
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Oleg Nesterov authored
Change oom_kill_task() to use do_send_sig_info(SEND_SIG_FORCED) instead of force_sig(SIGKILL). With the recent changes we do not need force_ to kill the CLONE_NEWPID tasks. And this is more correct. force_sig() can race with the exiting thread even if oom_kill_task() checks p->mm != NULL, while do_send_sig_info(group => true) kille the whole process. Signed-off-by:
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Oleg Nesterov authored
Cosmetic, rename the from_ancestor_ns argument in prepare_signal() paths. After the previous change it doesn't match the reality. Signed-off-by:
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Oleg Nesterov authored
force_sig_info() and friends have the special semantics for synchronous signals, this interface should not be used if the target is not current. And it needs the fixes, in particular the clearing of SIGNAL_UNKILLABLE is not exactly right. However there are callers which have to use force_ exactly because it clears SIGNAL_UNKILLABLE and thus it can kill the CLONE_NEWPID tasks, although this is almost always is wrong by various reasons. With this patch SEND_SIG_FORCED ignores SIGNAL_UNKILLABLE, like we do if the signal comes from the ancestor namespace. This makes the naming in prepare_signal() paths insane, fixed by the next cleanup. Note: this only affects SIGKILL/SIGSTOP, but this is enough for force_sig() abusers. Signed-off-by:
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Matt Fleming authored
As described in e6fa16ab ("signal: sigprocmask() should do retarget_shared_pending()") the modification of current->blocked is incorrect as we need to check whether the signal we're about to block is pending in the shared queue. Also, use the new helper function introduced in commit 5e6292c0 ("signal: add block_sigmask() for adding sigmask to current->blocked") which centralises the code for updating current->blocked after successfully delivering a signal and reduces the amount of duplicate code across architectures. In the past some architectures got this code wrong, so using this helper function should stop that from happening again. Acked-by:
Richard Kuo <rkuo@codeaurora.org> Signed-off-by:
Matt Fleming <matt.fleming@intel.com> Signed-off-by:
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Denys Vlasenko authored
PTRACE_SEIZE code is tested and ready for production use, remove the code which requires special bit in data argument to make PTRACE_SEIZE work. Strace team prepares for a new release of strace, and we would like to ship the code which uses PTRACE_SEIZE, preferably after this change goes into released kernel. Signed-off-by:
Denys Vlasenko <vda.linux@googlemail.com> Acked-by:
Tejun Heo <tj@kernel.org> Acked-by:
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Denys Vlasenko authored
PTRACE_EVENT_foo and PTRACE_O_TRACEfoo used to match. New PTRACE_EVENT_STOP is the first event which has no corresponding PTRACE_O_TRACE option. If we will ever want to add another such option, its PTRACE_EVENT's value will collide with PTRACE_EVENT_STOP's value. This patch changes PTRACE_EVENT_STOP value to prevent this. While at it, added a comment - the one atop PTRACE_EVENT block, saying "Wait extended result codes for the above trace options", is not true for PTRACE_EVENT_STOP. Signed-off-by:
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Denys Vlasenko authored
This can be used to close a few corner cases in strace where we get unwanted racy behavior after attach, but before we have a chance to set options (the notorious post-execve SIGTRAP comes to mind), and removes the need to track "did we set opts for this task" state in strace internals. While we are at it: Make it possible to extend SEIZE in the future with more functionality by passing non-zero 'addr' parameter. To that end, error out if 'addr' is non-zero. PTRACE_ATTACH did not (and still does not) have such check, and users (strace) do pass garbage there... let's avoid repeating this mistake with SEIZE. Set all task->ptrace bits in one operation - before this change, we were adding PT_SEIZED and PT_PTRACE_CAP with task->ptrace |= BIT ops. This was probably ok (not a bug), but let's be on a safer side. Changes since v2: use (unsigned long) casts instead of (long) ones, move PTRACE_SEIZE_DEVEL-related code to separate lines of code. Signed-off-by:
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Denys Vlasenko authored
Exchange PT_TRACESYSGOOD and PT_PTRACE_CAP bit positions, which makes PT_option bits contiguous and therefore makes code in ptrace_setoptions() much simpler. Every PTRACE_O_TRACEevent is defined to (1 << PTRACE_EVENT_event) instead of using explicit numeric constants, to ensure we don't mess up relationship between bit positions and event ids. PT_EVENT_FLAG_SHIFT was not particularly useful, PT_OPT_FLAG_SHIFT with value of PT_EVENT_FLAG_SHIFT-1 is easier to use. PT_TRACE_MASK constant is nuked, the only its use is replaced by (PTRACE_O_MASK << PT_OPT_FLAG_SHIFT). Signed-off-by:
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Denys Vlasenko authored
On ptrace(PTRACE_SETOPTIONS, pid, 0, <opts>), we used to set those option bits which are known, and then fail with -EINVAL if there are some unknown bits in <opts>. This is inconsistent with typical error handling, which does not change any state if input is invalid. This patch changes PTRACE_SETOPTIONS behavior so that in this case, we return -EINVAL and don't change any bits in task->ptrace. It's very unlikely that there is userspace code in the wild which will be affected by this change: it should have the form ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_BOGUSOPT) where PTRACE_O_BOGUSOPT is a constant unknown to the kernel. But kernel headers, naturally, don't contain any PTRACE_O_BOGUSOPTs, thus the only way userspace can use one if it defines one itself. I can't see why anyone would do such a thing deliberately. Signed-off-by: -
Oleg Nesterov authored
ptrace_event(PTRACE_EVENT_EXEC) sends SIGTRAP if PT_TRACE_EXEC is not set. This is because this SIGTRAP predates PTRACE_O_TRACEEXEC option, we do not need/want this with PT_SEIZED which can set the options during attach. Suggested-by:
Pedro Alves <palves@redhat.com> Signed-off-by:
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Oleg Nesterov authored
Another old/known problem. If the tracee is killed after it reports syscall_entry, it starts the syscall and debugger can't control this. This confuses the users and this creates the security problems for ptrace jailers. Change tracehook_report_syscall_entry() to return non-zero if killed, this instructs syscall_trace_enter() to abort the syscall. Reported-by:
Chris Evans <scarybeasts@gmail.com> Tested-by:
Indan Zupancic <indan@nul.nu> Signed-off-by:
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Namjae Jeon authored
Since '*outlen' is initialized to zero, it is currently possible to create a filename of length (FAT_LFN_LEN + 1) when utf8 is not enabled. To enforce the FAT_LFN_LEN limit, we must perform one less iteration. Signed-off-by:
Namjae Jeon <linkinjeon@gmail.com> Signed-off-by:
Ravishankar N <cyberax82@gmail.com> Acked-by:
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by:
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Namjae Jeon authored
xlate_to_uni() is called by vfat_build_slots() with sbi->nls_io as the final argument. nls_io can never be null at this point because the check is already being done in fat_fill_super() wherein the mount fails if it is null. Signed-off-by:
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Austin Boyle authored
Generalise NVRAM to support RAM with other size and offset, such as the 64 bytes of SRAM on the mcp7941x. [rdunlap@xenotime.net: fix printk format warning] Signed-off-by:
Austin Boyle <Austin.Boyle@aviatnet.com> Signed-off-by:
Wolfram Sang <w.sang@pengutronix.de> Signed-off-by:
Randy Dunlap <rdunlap@xenotime.net> Cc: David Anders <danders.dev@gmail.com> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by:
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David Anders authored
Do some cleanup of the comment sections as well as correct some formatting issues reported by checkpatch.pl. Signed-off-by:
David Anders <x0132446@ti.com> Signed-off-by:
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Wolfram Sang authored
No need to have two seperate if-blocks for setting up the irq. Signed-off-by:
David Anders <danders.dev@gmail.com> Cc: Austin Boyle <Austin.Boyle@aviatnet.com> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by:
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Wolfram Sang authored
The chip_desc table is suboptimal. Currently it requires an entry for every new chip type, even if it is empty. This has already been forgotten for the ds1388. Refactor the code, so new entries are only needed, when they chip type really needs a (non-empty) description. Also make the table visually more appealing. Signed-off-by:
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Ashish Jangam authored
RTC Driver for Dialog Semiconductor DA9052/53 PMICs. This patch is functionally tested on Samsung SMDKV6410. [akpm@linux-foundation.org: clean up file header layout, remove unneeded initialisation of local arrays] Signed-off-by:
David Dajun Chen <dchen@diasemi.com> Signed-off-by:
Ashish Jangam <ashish.jangam@kpitcummins.com> Cc: Paul Gortmaker <p_gortmaker@yahoo.com> Cc: David Dajun Chen <dchen@diasemi.com> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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Kevin Liu authored
drivers/rtc/rtc-max8925.c: fix alarm->enabled mistake in max8925_rtc_read_alarm/max8925_rtc_set_alarm max8925_rtc_read_alarm() should set alrm->enabled based on both ALARM_IRQ_MASK and ALARM_CTRL setting. max8925_rtc_set_alarm() should enable/disable alarm according to ALARM_CTRL reg setting. Signed-off-by:
Kevin Liu <kliu5@marvell.com> Signed-off-by:
Haojian Zhuang <haojian.zhuang@marvell.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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Kevin Liu authored
max8925_rtc_read_alarm should always return 0 with success Signed-off-by:
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Navin P authored
Signed-off-by:
Navin P <zicrim@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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Yong Zhang authored
Since commit e58aa3d2 ("genirq: run irq handlers with interrupts disabled") we run all interrupt handlers with interrupts disabled and we even check and yell when an interrupt handler returns with interrupts enabled - see commit b738a50a ("genirq: warn when handler enables interrupts"). So now this flag is a NOOP and can be removed. Signed-off-by:
Yong Zhang <yong.zhang0@gmail.com> Acked-by:
Linus Walleij <linus.walleij@linaro.org> Acked-by:
Wan ZongShun <mcuos.com@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by:
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Venu Byravarasu authored
Following changes are made as part of this change: 1. As TWL RTC supports periodic interrupt, the correct event should be RTC_PF instead of RTC_UF. 2. No need to initialize variable "events" to 0 & then OR it with the event values. Hence fixing it. Signed-off-by:
Venu Byravarasu <vbyravarasu@nvidia.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by:
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Venu Byravarasu authored
For clearing RTC interrupt, programming ALARM bit only is sufficient, as all other bits are any way not affected by writing 0 to them. Hence removed unwanted OR operation. Signed-off-by:
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Venu Byravarasu authored
As part of probe, before enabling RTC, RTC_CTRL register is read to check if it is already running. If RTC is used by kernel alone, then this read is not required. Even if RTC was enabled already by boot loader, setting STOP_RTC bit again should not harm. Hence removed unwanted read operation. Signed-off-by:
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Venu Byravarasu authored
As the TWL RTC driver has a cached copy of enabled RTC interrupt bits in variable rtc_irq_bits, that can be checked before really setting or masking any of the interrupt bits. Signed-off-by:
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