- 11 Aug, 2010 40 commits
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Oleg Nesterov authored
alloc_pidmap() calculates max_scan so that if the initial offset != 0 we inspect the first map->page twice. This is correct, we want to find the unused bits < offset in this bitmap block. Add the comment. But it doesn't make any sense to stop the find_next_offset() loop when we are looking into this map->page for the second time. We have already already checked the bits >= offset during the first attempt, it is fine to do this again, no matter if we succeed this time or not. Remove this hard-to-understand code. It optimizes the very unlikely case when we are going to fail, but slows down the more likely case. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Salman Qazi <sqazi@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Salman authored
A program that repeatedly forks and waits is susceptible to having the same pid repeated, especially when it competes with another instance of the same program. This is really bad for bash implementation. Furthermore, many shell scripts assume that pid numbers will not be used for some length of time. Race Description: A B // pid == offset == n // pid == offset == n + 1 test_and_set_bit(offset, map->page) test_and_set_bit(offset, map->page); pid_ns->last_pid = pid; pid_ns->last_pid = pid; // pid == n + 1 is freed (wait()) // Next fork()... last = pid_ns->last_pid; // == n pid = last + 1; Code to reproduce it (Running multiple instances is more effective): #include <errno.h> #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> // The distance mod 32768 between two pids, where the first pid is expected // to be smaller than the second. int PidDistance(pid_t first, pid_t second) { return (second + 32768 - first) % 32768; } int main(int argc, char* argv[]) { int failed = 0; pid_t last_pid = 0; int i; printf("%d\n", sizeof(pid_t)); for (i = 0; i < 10000000; ++i) { if (i % 32786 == 0) printf("Iter: %d\n", i/32768); int child_exit_code = i % 256; pid_t pid = fork(); if (pid == -1) { fprintf(stderr, "fork failed, iteration %d, errno=%d", i, errno); exit(1); } if (pid == 0) { // Child exit(child_exit_code); } else { // Parent if (i > 0) { int distance = PidDistance(last_pid, pid); if (distance == 0 || distance > 30000) { fprintf(stderr, "Unexpected pid sequence: previous fork: pid=%d, " "current fork: pid=%d for iteration=%d.\n", last_pid, pid, i); failed = 1; } } last_pid = pid; int status; int reaped = wait(&status); if (reaped != pid) { fprintf(stderr, "Wait return value: expected pid=%d, " "got %d, iteration %d\n", pid, reaped, i); failed = 1; } else if (WEXITSTATUS(status) != child_exit_code) { fprintf(stderr, "Unexpected exit status %x, iteration %d\n", WEXITSTATUS(status), i); failed = 1; } } } exit(failed); } Thanks to Ted Tso for the key ideas of this implementation. Signed-off-by:Salman Qazi <sqazi@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
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Alexey Dobriyan authored
Fix this garbage happening quite often: ==> sda: scsi 3:0:0:0: CD-ROM TOSHIBA ==> sda1 sda2 sda3 sda4 <sr0: scsi3-mmc drive: 24x/24x writer dvd-ram cd/rw xa/form2 cdda tray ^^^ Uniform CD-ROM driver Revision: 3.20 sr 3:0:0:0: Attached scsi CD-ROM sr0 ==> sda5 sda6 sda7 > Make "sda: sda1 ..." lines actually lines. Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Jens Rottmann authored
The MFGPT hardware may be set up only once, therefore cs5535_mfgpt_free_timer() didn't re-set the timer's "avail" bit. However if a timer is freed before it has actually been in use then it may be made available again. Signed-off-by:
Jens Rottmann <JRottmann@LiPPERTEmbedded.de> Acked-by:
Andres Salomon <dilinger@queued.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jordan Crouse <jordan@cosmicpenguin.net> Signed-off-by:
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Julia Lawall authored
Add a spin_unlock_irqrestore missing on the error path. Converting the return to break leads to the spin_unlock_irqrestore at the end of the function. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression E1; @@ * spin_lock_irqsave(E1,...); <+... when != E1 if (...) { ... when != E1 * return ...; } ...+> * spin_unlock_irqrestore(E1,...); // </smpl> Signed-off-by:
Julia Lawall <julia@diku.dk> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by:
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Yinghai Lu authored
Print out the reg spacing and size for spmi and smbios so BIOS developers can make them consistent. Also remove extra PFX on the duplicating path. Signed-off-by:
Yinghai Lu <yinghai@kernel.org> Cc: Corey Minyard <minyard@acm.org> Cc: Matthew Garrett <mjg@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Myron Stowe <myron.stowe@hp.com> Signed-off-by:
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Yinghai Lu authored
Free the temporary info struct when we have duplicated ones. Signed-off-by:
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Justin P. Mattock authored
Fix a warning message generated by GCC, and also updates a web address pointing to a pdf containing information. CC [M] drivers/char/ipmi/ipmi_si_intf.o drivers/char/ipmi/ipmi_si_intf.c: In function 'try_init_spmi': drivers/char/ipmi/ipmi_si_intf.c:2016:8: warning: variable 'addr_space' set but not used Signed-off-by:
Sergey V. <sftp.mtuci@gmail.com> Signed-off-by:
Justin P. Mattock <justinmattock@gmail.com> Acked-by:
Corey Minyard <minyard@acm.org> Signed-off-by:
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Robert P. J. Day authored
Since the entire fs/proc directory is conditionally included based on CONFIG_PROC_FS, it's redundant to check that same variable within that directory. Signed-off-by:
Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by:
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Nathan Lynch authored
If signalfd is used to consume a signal generated by a POSIX interval timer or POSIX message queue, the ssi_int field does not reflect the data (sigevent->sigev_value) supplied to timer_create(2) or mq_notify(3). (The ssi_ptr field, however, is filled in.) This behavior differs from signalfd's treatment of sigqueue-generated signals -- see the default case in signalfd_copyinfo. It also gives results that differ from the case when a signal is handled conventionally via a sigaction-registered handler. So, set signalfd_siginfo->ssi_int in the remaining cases (__SI_TIMER, __SI_MESGQ) where ssi_ptr is set. akpm: a non-back-compatible change. Merge into -stable to minimise the number of kernels which are in the field and which miss this feature. Signed-off-by:
Nathan Lynch <ntl@pobox.com> Acked-by:
Davide Libenzi <davidel@xmailserver.org> Cc: <stable@kernel.org> Signed-off-by:
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Oleg Nesterov authored
exit_ptrace() takes tasklist_lock unconditionally. We need this lock to avoid the race with ptrace_traceme(), it acts as a barrier. Change its caller, forget_original_parent(), to call exit_ptrace() under tasklist_lock. Change exit_ptrace() to drop and reacquire this lock if needed. This allows us to add the fastpath list_empty(ptraced) check. In the likely no-tracees case exit_ptrace() just returns and we avoid the lock() + unlock() sequence. "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> suggested to add this check, and he reports that this change adds about 11% improvement in some tests. Suggested-and-tested-by:
"Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
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KOSAKI Motohiro authored
We have zone_to_nid(). this patch convert all existing users of zone->zone_pgdat->node_id. Signed-off-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by:
Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Nishimura Daisuke <d-nishimura@mtf.biglobe.ne.jp> Signed-off-by:
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KOSAKI Motohiro authored
mem_cgroup_soft_limit_reclaim() has zone, nid and zid argument. but nid and zid can be calculated from zone. So remove it. Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by:
Mel Gorman <mel@csn.ul.ie> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Nishimura Daisuke <d-nishimura@mtf.biglobe.ne.jp> Signed-off-by:
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KOSAKI Motohiro authored
Currently mem_cgroup_shrink_node_zone() call shrink_zone() directly. thus it doesn't need to initialize sc.nodemask because shrink_zone() doesn't use it at all. Signed-off-by:
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KOSAKI Motohiro authored
sc.nr_reclaimed and sc.nr_scanned have already been initialized few lines above "struct scan_control sc = {}" statement. So, This patch remove this unnecessary code. Signed-off-by: -
KOSAKI Motohiro authored
Currently, mem_cgroup_shrink_node_zone() initialize sc.nr_to_reclaim as 0. It mean shrink_zone() only scan 32 pages and immediately return even if it doesn't reclaim any pages. This patch fixes it. Signed-off-by:
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KAMEZAWA Hiroyuki authored
Now, memory cgroup increments css(cgroup subsys state)'s reference count per a charged page. And the reference count is kept until the page is uncharged. But this has 2 bad effect. 1. Because css_get/put calls atomic_inc()/dec, heavy call of them on large smp will not scale well. 2. Because css's refcnt cannot be in a state as "ready-to-release", cgroup's notify_on_release handler can't work with memcg. 3. css's refcnt is atomic_t, it means smaller than 32bit. Maybe too small. This has been a problem since the 1st merge of memcg. This is a trial to remove css's refcnt per a page. Even if we remove refcnt, pre_destroy() does enough synchronization as - check res->usage == 0. - check no pages on LRU. This patch removes css's refcnt per page. Even after this patch, at the 1st look, it seems css_get() is still called in try_charge(). But the logic is. - If a memcg of mm->owner is cached one, consume_stock() will work. At success, return immediately. - If consume_stock returns false, css_get() is called and go to slow path which may be blocked. At the end of slow path, css_put() is called and restart from the start if necessary. So, in the fast path, we don't call css_get() and can avoid access to shared counter. This patch can make the most possible case fast. Here is a result of multi-threaded page fault benchmark. [Before] 25.32% multi-fault-all [kernel.kallsyms] [k] clear_page_c 9.30% multi-fault-all [kernel.kallsyms] [k] _raw_spin_lock_irqsave 8.02% multi-fault-all [kernel.kallsyms] [k] try_get_mem_cgroup_from_mm <=====(*) 7.83% multi-fault-all [kernel.kallsyms] [k] down_read_trylock 5.38% multi-fault-all [kernel.kallsyms] [k] __css_put 5.29% multi-fault-all [kernel.kallsyms] [k] __alloc_pages_nodemask 4.92% multi-fault-all [kernel.kallsyms] [k] _raw_spin_lock_irq 4.24% multi-fault-all [kernel.kallsyms] [k] up_read 3.53% multi-fault-all [kernel.kallsyms] [k] css_put 2.11% multi-fault-all [kernel.kallsyms] [k] handle_mm_fault 1.76% multi-fault-all [kernel.kallsyms] [k] __rmqueue 1.64% multi-fault-all [kernel.kallsyms] [k] __mem_cgroup_commit_charge [After] 28.41% multi-fault-all [kernel.kallsyms] [k] clear_page_c 10.08% multi-fault-all [kernel.kallsyms] [k] _raw_spin_lock_irq 9.58% multi-fault-all [kernel.kallsyms] [k] down_read_trylock 9.38% multi-fault-all [kernel.kallsyms] [k] _raw_spin_lock_irqsave 5.86% multi-fault-all [kernel.kallsyms] [k] __alloc_pages_nodemask 5.65% multi-fault-all [kernel.kallsyms] [k] up_read 2.82% multi-fault-all [kernel.kallsyms] [k] handle_mm_fault 2.64% multi-fault-all [kernel.kallsyms] [k] mem_cgroup_add_lru_list 2.48% multi-fault-all [kernel.kallsyms] [k] __mem_cgroup_commit_charge Then, 8.02% of try_get_mem_cgroup_from_mm() disappears because this patch removes css_tryget() in it. (But yes, this is an extreme case.) Signed-off-by:Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by:
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KAMEZAWA Hiroyuki authored
When the OOM killer scans task, it check a task is under memcg or not when it's called via memcg's context. But, as Oleg pointed out, a thread group leader may have NULL ->mm and task_in_mem_cgroup() may do wrong decision. We have to use find_lock_task_mm() in memcg as generic OOM-Killer does. Signed-off-by:
Minchan Kim <minchan.kim@gmail.com> Signed-off-by:
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Daisuke Nishimura authored
mem_cgroup_charge_common() is always called with @mem = NULL, so it's meaningless. This patch removes it. Signed-off-by:
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Daisuke Nishimura authored
- try_get_mem_cgroup_from_mm() calls rcu_read_lock/unlock by itself, so we don't have to call them in task_in_mem_cgroup(). - *mz is not used in __mem_cgroup_uncharge_common(). - we don't have to call lookup_page_cgroup() in mem_cgroup_end_migration() after we've cleared PCG_MIGRATION of @oldpage. - remove empty comment. - remove redundant empty line in mem_cgroup_cache_charge(). Signed-off-by:
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KAMEZAWA Hiroyuki authored
Now, for checking a memcg is under task-account-moving, we do css_tryget() against mc.to and mc.from. But this is just complicating things. This patch makes the check easier. This patch adds a spinlock to move_charge_struct and guard modification of mc.to and mc.from. By this, we don't have to think about complicated races arount this not-critical path. [balbir@linux.vnet.ibm.com: don't crash on a null memcg being passed] Signed-off-by:
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KAMEZAWA Hiroyuki authored
mem_cgroup_try_charge() has a big loop in it and seems to be hard to read. Most of routines are for slow path. This patch moves codes out from the loop and make it clear what's done. Summary: - refactoring a function to detect a memcg is under acccount move or not. - refactoring a function to wait for the end of moving task acct. - refactoring a main loop('s slow path) as a function and make it clear why we retry or quit by return code. - add fatal_signal_pending() check for bypassing charge loops. Signed-off-by: -
KAMEZAWA Hiroyuki authored
It's 11 months since we changed swap_map[] to indicates SWAP_HAS_CACHE. Since that, memcg's swap accounting has been very stable and it seems it can be maintained. So, I'd like to remove EXPERIMENTAL from the config. Acked-by:
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Chris Wright authored
The cgroup device whitelist code gets confused when trying to grant permission to a disk partition that is not currently open. Part of blkdev_open() includes __blkdev_get() on the whole disk. Basically, the only ways to reliably allow a cgroup access to a partition on a block device when using the whitelist are to 1) also give it access to the whole block device or 2) make sure the partition is already open in a different context. The patch avoids the cgroup check for the whole disk case when opening a partition. Addresses https://bugzilla.redhat.com/show_bug.cgi?id=589662Signed-off-by:
Chris Wright <chrisw@sous-sol.org> Acked-by:
Serge E. Hallyn <serue@us.ibm.com> Tested-by:
Vivek Goyal <vgoyal@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: "Daniel P. Berrange" <berrange@redhat.com> Cc: <stable@kernel.org> Signed-off-by:
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Dan Carpenter authored
The original code didn't leave enough space for a NULL terminator. These strings are copied with strcpy() into fixed length buffers in cgroup_root_from_opts(). Signed-off-by:
Dan Carpenter <error27@gmail.com> Acked-by:
Serge E. Hallyn <serge@hallyn.com> Reviewd-by:
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Randy Dunlap authored
Fix typos & grammar. Use CPU instead of cpu in text. Signed-off-by:
Randy Dunlap <randy.dunlap@oracle.com> Acked-by:
Steffen Klassert <steffen.klassert@secunet.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Huang Shijie authored
The exception.txt has been removed from the Documentation directory. So update the index file for it. Signed-off-by:
Huang Shijie <shijie8@gmail.com> Signed-off-by:
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Ben Hutchings authored
$ rm -rf build $ mkdir build $ cp .config build $ make O=build htmldocs ... xmlto: linux-2.6/build/Documentation/DocBook/media.xml does not validate (status 3) xmlto: Fix document syntax or use --skip-validation option linux-2.6/build/Documentation/DocBook/media.xml:4: warning: failed to load external entity "linux-2.6/build/Documentation/DocBook/media-entities.tmpl" We need the xmldoclinks built for any document types built from the XML sources. Signed-off-by:
Ben Hutchings <ben@decadent.org.uk> Acked-by:
Andy Whitcroft <apw@canonical.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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Joe Perches authored
Commit 1d794e3b ("Staging: wavelan: delete the driver") removed the source, so remove the documentation as well. Signed-off-by:
Joe Perches <joe@perches.com> Cc: Jean Tourrilhes <jt@hpl.hp.com> Acked-by:
Randy Dunlap <rdunlap@xenotime.net> Signed-off-by:
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Randy Dunlap authored
Fix mtd/nand_base.c kernel-doc warnings and typos. Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'mtd' Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'ofs' Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'len' Warning(drivers/mtd/nand/nand_base.c:893): No description found for parameter 'invert' Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'mtd' Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'ofs' Warning(drivers/mtd/nand/nand_base.c:930): No description found for parameter 'len' Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'mtd' Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'ofs' Warning(drivers/mtd/nand/nand_base.c:987): No description found for parameter 'len' Warning(drivers/mtd/nand/nand_base.c:2087): No description found for parameter 'len' Signed-off-by:
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Randy Dunlap authored
Fix (delete) empty kernel-doc lines/warnings: Warning(drivers/message/fusion/mptbase.c:6916): bad line: Warning(drivers/message/fusion/mptbase.c:7060): bad line: Signed-off-by:
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Changli Gao authored
Signed-off-by:
Changli Gao <xiaosuo@gmail.com> Signed-off-by:
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Andrew Morton authored
Cc: Kulikov Vasiliy <segooon@gmail.com> Signed-off-by:
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Kulikov Vasiliy authored
If iga_init() fails, code releases resources and continues to use it. It seems that after releasing resources 'return' should be. Signed-off-by:
Kulikov Vasiliy <segooon@gmail.com> Signed-off-by:
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Daniel De Graaf authored
When we setup up the VMA flags for the mmap flag and we end up using the fallback mmap functionality we set the vma->vm_flags |= VM_IO. However we neglect to propagate the flag to the vma->vm_page_prot. This bug was found when Linux kernel was running under Xen. In that scenario, any page that has VM_IO flag to it, means that it MUST be a MMIO/VRAM backend memory , _not_ System RAM. That is what the fbmem.c does: sets VM_IO, ioremaps the region - everything is peachy. Well, not exactly. The vm_page_prot does not get the relevant PTE flags set (_PAGE_IOMAP) which under Xen is a death-kneel to pages that are referencing real physical devices but don't have that flag set. This patch fixes this. Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
Daniel De Graaf <dgdegra@tycho.nsa.gov> Tested-by:
Eamon Walsh <ewalsh@tycho.nsa.gov> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by:
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Maurus Cuelenaere authored
Since "s3c-fb: Automatically calculate pixel clock when none is given", there's no need for manually calculating the pixel clock anymore so remove these lines and add the correct refresh rate where appropriately. Signed-off-by:
Maurus Cuelenaere <mcuelenaere@gmail.com> Cc: Pawel Osciak <p.osciak@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: InKi Dae <inki.dae@samsung.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by:
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Maurus Cuelenaere authored
Add a simple algorithm which calculates the pixel clock based on the video mode parameters. This is only done when no pixel clock is supplied through the platform data. This allows drivers to omit the pixel clock data and thus share the algorithm used for calculating it. Signed-off-by:
Donghwa Lee <yiffie9819@gmail.com> Signed-off-by:
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Pawel Osciak authored
S5PV210 SoCs allow enabling/disabling DMA channels per window. For a window to display data from framebuffer memory, its channel has to be enabled. Signed-off-by:
Pawel Osciak <p.osciak@samsung.com> Signed-off-by:
Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by:
Kyungmin Park <kyungmin.park@samsung.com> Cc: InKi Dae <inki.dae@samsung.com> Cc: Ben Dooks <ben-linux@fluff.org> Signed-off-by:
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Marek Szyprowski authored
This patch fixes the following section mismatch errors: WARNING: vmlinux.o(.data+0x20b40): Section mismatch in reference from the variable s3c_fb_driver_ids to the (unknown reference) .devinit.data:(unknown) The variable s3c_fb_driver_ids references the (unknown reference) __devinitdata (unknown) If the reference is valid then annotate the variable with __init* or __refdata (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, WARNING: vmlinux.o(.data+0x20b58): Section mismatch in reference from the variable s3c_fb_driver_ids to the (unknown reference) .devinit.data:(unknown) The variable s3c_fb_driver_ids references the (unknown reference) __devinitdata (unknown) If the reference is valid then annotate the variable with __init* or __refdata (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, WARNING: vmlinux.o(.data+0x20b70): Section mismatch in reference from the variable s3c_fb_driver_ids to the (unknown reference) .devinit.data:(unknown) The variable s3c_fb_driver_ids references the (unknown reference) __devinitdata (unknown) If the reference is valid then annotate the variable with __init* or __refdata (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, Signed-off-by:
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Pawel Osciak authored
Newer hardware (S3C6410, S5P) have the ability to block updates from shadow registers during reconfiguration. Add protect calls for set_par and clear protection when resetting. Signed-off-by:
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