FRV does not require a ZONE_DMA, so all DMA'able pages that aren't highmem
should be in ZONE_NORMAL.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_ALIGNMENT_TRAP is never set on arm26.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When removing set_native_irq I missed the fact that it was
called in a couple of places that were compiled even when
SMP support is disabled. And since the irq_desc[].affinity
field only exists in SMP things broke.
Thanks to Simon Arlott <simon@arlott.org> for spotting this.
There are a couple of ways to fix this but the simplest one
is to just remove the assignments. The affinity field is only
used to display a value to the user, and nothing on either i386
or x86_64 reads it or depends on it being any particlua value,
so skipping the assignment is safe. The assignment that
is being removed is just for the initial affinity value before
the user explicitly sets it. The irq_desc array initializes
this field to CPU_MASK_ALL so the field is initialized to
a reasonable value in the SMP case without being set.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the PCI controller OBP node lacks an interrupt-map
and interrupt-map-mask property, we need to form the
INO by hand. The PCI swizzle logic was not doing that
properly.
This was a regression added by the of_device code.
Signed-off-by: David S. Miller <davem@davemloft.net>
smp_cpus_done is too early for us... before we even do a device
inventory! Move update_cr16_clocksource into the tail end of
processor_probe() and stub it out on CONFIG_SMP=n builds.
Verified that clocksource0 is properly updated to use jiffies
on an SMP build.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
So move the code to be called by smp_cpus_done, which is
after we've figured out if there's more than one cpu
actually present.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Use MIPS_CPU_IRQ_BASE instead of own define.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
pcibios_fixup_device_resources() is called by pcibios_fixup_bus() which is
marked as __devinit.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Many Makefiles in arch/mips have EXTRA_AFLAGS := $(CFLAGS) line. This
is redundant while AFLAGS contains $(cflags-y) and any options only
listed in CFLAGS (not in cflags-y) should be unnecessary for asm
sources.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This reverts commit aeeddc1435, which was
half-baked and broken. It just resulted in compile errors, since
cpufreq_register_driver() still changes the 'driver_data' by setting
bits in the flags field. So claiming it is 'const' _really_ doesn't
work.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeremy Fitzhardinge suggested the use of -freg-struct-return, which does
structure-returns (such as when using pte_t) in registers instead of on
the stack.
that is indeed so, and this option reduced the kernel size a bit:
text data bss dec hex filename
4799506 543456 3760128 9103090 8ae6f2 vmlinux.before
4798117 543456 3760128 9101701 8ae185 vmlinux.after
the resulting kernel booted fine on my testbox. Lets go for it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* master.kernel.org:/pub/scm/linux/kernel/git/kyle/parisc-2.6: (78 commits)
[PARISC] Use symbolic last syscall in __NR_Linux_syscalls
[PARISC] Add missing statfs64 and fstatfs64 syscalls
Revert "[PARISC] Optimize TLB flush on SMP systems"
[PARISC] Compat signal fixes for 64-bit parisc
[PARISC] Reorder syscalls to match unistd.h
Revert "[PATCH] make kernel/signal.c:kill_proc_info() static"
[PARISC] fix sys_rt_sigqueueinfo
[PARISC] fix section mismatch warnings in harmony sound driver
[PARISC] do not export get_register/set_register
[PARISC] add ENTRY()/ENDPROC() and simplify assembly of HP/UX emulation code
[PARISC] convert to use CONFIG_64BIT instead of __LP64__
[PARISC] use CONFIG_64BIT instead of __LP64__
[PARISC] add ASM_EXCEPTIONTABLE_ENTRY() macro
[PARISC] more ENTRY(), ENDPROC(), END() conversions
[PARISC] fix ENTRY() and ENDPROC() for 64bit-parisc
[PARISC] Fixes /proc/cpuinfo cache output on B160L
[PARISC] implement standard ENTRY(), END() and ENDPROC()
[PARISC] kill ENTRY_SYS_CPUS
[PARISC] clean up debugging printks in smp.c
[PARISC] factor syscall_restart code out of do_signal
...
Fix conflict in include/linux/sched.h due to kill_proc_info() being made
publicly available to PARISC again.
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
[MIPS] Fix port 0 mac address for mips mv6434x platforms
[SERIAL] serial_txx9 driver update
Revert "[PATCH] Generic ioremap_page_range: mips conversion"
[MIPS] Cobalt: Rename "Colo" MTD partition to "firmware".
[MIPS] SMP: Get smp_tune_scheduling to do something useful.
[MIPS] Add basic SMARTMIPS ASE support
The problem: After moving an interrupt when is it safe to teardown
the data structures for receiving the interrupt at the old location?
With a normal pci device it is possible to issue a read to a device
to flush all posted writes. This does not work for the oldest ioapics
because they are on a 3-wire apic bus which is a completely different
data path. For some more modern ioapics when everything is using
front side bus delivery you can flush interrupts by simply issuing a
read to the ioapic. For other modern ioapics emperical testing has
shown that this does not work.
So it appears the only reliable way to know the last of the irqs from an
ioapic have been received from before the ioapic was reprogrammed is to
received the first irq from the ioapic from after it was reprogrammed.
Once we know the last irq message has been received from an ioapic
into a local apic we then need to know that irq message has been
processed through the local apics.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For the ISA irqs we reserve 16 vectors. This patch adds constants for
those vectors and modifies the code to use them. Making the code a
little clearer and making it possible to move these vectors in the future.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The code in io_apic.c and in i8259.c currently hardcode the same
vector for the timer interrupt so there is no reason for a special
assignment for the timer as the setup for the i8259 already takes care
of this.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently assign_irq_vector works mostly by side effect and returns
the results of it's changes to the caller. Which makes for a lot of
arguments to pass/return and confusion as to what to do if you need
the status but you aren't calling assign_irq_vector.
This patch stops returning values from assign_irq_vector that can be
retrieved just as easily by examining irq_cfg, and modifies the
callers to retrive those values from irq_cfg when they need them.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the io_apic.c has several parallel arrays for different
kinds of data that can be know about an irq. The parallel arrays
make the code harder to maintain and make it difficult to remove
the static limits on the number of the number of irqs.
This patch pushes irq_data and irq_vector into a irq_cfg array and
updates the code to use it.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NR_IRQ_VECTORS is currently a compatiblity define set to NR_IRQs.
This patch updates the users of NR_IRQ_VECTORS to use NR_IRQs instead
so that NR_IRQ_VECTORS can be removed.
There is still shared code with arch/i386 that uses NR_IRQ_VECTORS
so we can't remove the #define just yet :(
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we have an irq that comes from multiple io_apic pins the FINAL action
(which is io_apic_sync or nothing) needs to be called for every entry or
else if the two pins come from different io_apics we may not wait until
after the action happens on the io_apic.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For some reason the code has been picking TARGET_CPUS when asked to
set the affinity to an empty set of cpus. That is just silly it's
extra work. Instead if there are no cpus to set the affinity to we
should just give up immediately. That is simpler and a little more
intuitive.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we have two routines that do practically the same thing
setup_IO_APIC_irq and io_apic_set_pci_routing. This patch makes
setup_IO_APIC_irq the common factor of these two previous routines.
For setup_IO_APIC_irq all that was needed was to pass the trigger
and polarity to make the code a proper subset of io_apic_set_pci_routing.
Hopefully consolidating these two routines will improve maintenance
there were several differences that simply appear to be one routine
or the other getting it wrong.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch replaces all instances of "set_native_irq_info(irq, mask)"
with "irq_desc[irq].affinity = mask". The latter form is clearer
uses fewer abstractions, and makes access to this field uniform
accross different architectures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
By precomputing old_mask I remove an extra if statement, remove an
indentation level and make the code slightly easier to read.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2ff2d3d747.
Uwe Bugla reports that he cannot mount a floppy drive any more, and Jiri
Slaby bisected it down to this commit.
Benjamin LaHaise also points out that this is a big hot-path, and that
interrupt delivery while idle is very common and should not go through
all these expensive gyrations.
Fix up conflicts in arch/i386/kernel/apic.c and arch/i386/kernel/irq.c
due to other unrelated irq changes.
Cc: Stephane Eranian <eranian@hpl.hp.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Uwe Bugla <uwe.bugla@gmx.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
aware
Since TEXT_OFFSET is meant to determine RAM location for kernel use,
itshould affect .data and .bss initial mapping in the XIP case.
Otherwise a XIP kernel would crash if TEXT_OFFSET gets somewhat larger
than 2MB.
Corresponding code is also moved up a bit to be near the similar .text
mapping code making the whole a bit more straight forward to understand.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since commit 2552fc27ff XIP kernels failed
to boot because (_end - PAGE_OFFSET - 1) is much smaller than the size
of the kernel text and data in the XIP case, causing the kernel not to
be entirely mapped.
Even in the non-XIP case, the use of (_end - PAGE_OFFSET - 1) is wrong
because it produces a too large value if TEXT_OFFSET is larger than 1MB.
Finally the original code was performing one loop too many.
Let's break the loop when the section pointer has passed the last byte
of the kernel instead.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The new gpio_direction_input() and gpio_direction_output() functions
were both enabling output mode. When configuring a GPIO for input mode,
you need to program the ODR (Output Disable Register).
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The duplicate file "include/asm-arm/arch-at91rm9200/entry-macro.S" can
be removed - it was already moved to include/asm-arm/arch-at91/.
Fix 3 small typo's - two in comments, and the incorrect clock was
specified for the LCD device.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add the Armzone QT2410 to the list of built
machines in the s3c2410_defconfig
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds trivial support for SMARTMIPS extension. This extension
is currently implemented by 4KS[CD] CPUs.
Basically it saves/restores ACX register, which is part of the SMARTMIPS
ASE, when needed. This patch does *not* add any support for Smartmips MMU
features.
Futhermore this patch does not add explicit support for 4KS[CD] CPUs since
they are respectively mips32 and mips32r2 compliant. So with the current
processor configuration, a platform that has such CPUs needs to select
both configs:
CPU_HAS_SMARTMIPS
SYS_HAS_CPU_MIPS32_R[12]
This is due to the processor configuration which is mixing up all the
architecture variants and the processor types.
The drawback of this, is that we currently pass '-march=mips32' option to
gcc when building a kernel instead of '-march=4ksc' for 4KSC case. This
can lead to a kernel image a little bit bigger than required.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Since $(ARCH) is always "s390" we can replace it with "s390".
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With CONFIG_SHARED_KERNEL the kernel text segment that might be in a
read only memory sections starts at 1MB. Memory between 0x12000 and
0x100000 is unused then. Free this, so we have appr. an extra MB
of memory available.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Clear only memory from __bss_start to __bss_stop when clearing the bss
section. Not until _end, which currently happens to be the same.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To avoid ugly warings for older gccs, we replace
BUG() with "return NULL", which is just as well.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Setup.h has been misused for ipl related stuff in the past. We now move
everything, which has to do with ipl and reipl to a new header file named
"ipl.h".
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Replace two stidp inline assemblies with one global implementation.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Force reading of *in_sync in while loop. Loops where the content that
is checked for is changed by a different cpu always should have some
sort of barrier() semantics.
Otherwise this might lead to very subtle bugs.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Disable ZONE_DMA on 31-bit. All memory is addressable by all
devices and we do not need any special memory pool.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce __smp_call_function_map which calls a function on all cpus
given with a cpumask_t. Use it to implement smp_call_function and
smp_call_function_on. Replace smp_ext_bitcall_others with smp_ext_bitcall
and a for_each_cpu_mask loop. Use a cpumask_t instead of an atomic_t for
cpu counting and print a warning if preempt is on in
__smp_call_function_map().
Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The new delay implementation uses the clock comparator and an external
interrupt even if it is called disabled for interrupts. To do this
all external interrupt source except clock comparator are switched of
before enabling external interrupts. The external interrupt at the
end of the delay period may not execute softirqs or we can end up in a
dead-lock.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Based on the discussion last december (http://lkml.org/lkml/2006/12/20/241),
this patch
- adds gpio_direction_input/output functions to
generic.c instead of making them inline,
- fixes comment and includes and uses inline functions
instead of macros in gpio.h
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on the discussion last december (http://lkml.org/lkml/2006/12/20/242),
this patch:
- moves the PXA_LAST_GPIO check into pxa_gpio_mode
- fixes comment and includes in gpio.h
- replaces the gpio_set/get_value macros with inline
functions and adds a non-inline version to avoid
code explosion when gpio is not a constant.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There was OpenVZ specific bug rendering some cpufreq drivers unusable on SMP.
In short, when cpufreq code thinks it confined itself to needed cpu by means
of set_cpus_allowed() to execute rdmsr, some "virtual cpu" feature can migrate
process to anywhere. This triggers bugons and does wrong things in general.
This got fixed by introducing rdmsr_on_cpu and wrmsr_on_cpu executing rdmsr
and wrmsr on given physical cpu by means of smp_call_function_single().
Dave Jones mentioned cpufreq might be not only user of rdmsr_on_cpu() and
wrmsr_on_cpu(), so I'm putting them into arch/{i386,x86_64}/lib/ .
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
The rename of the AT91 subtree from mach-at91rm9200 to mach-at91
(to accomodate at91sam926x processors) was incomplete. It needs
this patch to be able to build again.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
[NET] Eliminate user-selectable CONFIG_MV643XX_ETH_[012]
[MIPS] Drop __init from init_8259A()
[MIPS] Fix Kconfig typo bug
[MIPS] Fix double signal on trap and break instruction
[MIPS] sigset_32 has been made redundand by compat_sigset_t.
[MIPS] emma2rh: Remove needless <asm/i8259.h> inclusion.
[MIPS] Add MTD device support for Cobalt
Remove the use of CONFIG_MV643XX_ETH_[012] variables on most platforms.
Instead, platform-specific code enables the ports supported by the
hardware. After this patch, these config variables are only used in
arch/ppc, so also move them from drivers/net/Kconfig to arch/ppc/Kconfig.
Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Jeff Garzik <jeff@garzik.org>
Cc: Paul Mackerras <paulus@samba.org>
init_8259A() is called from i8259A_resume() so should not be marked as
__init. And add some tests for whether 8259A was already initialized
or not.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit broke gdb, since any BREAK or TRAP instruction cause SIGSEGV.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch has added MTD device support for Cobalt.
Moreover, removes old type FlashROM support.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
On S3C24XX architecture, select CONFIG_NO_IOPORT
as we only have memory based IO.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The rename of the AT91 subtree from mach-at91rm9200 to mach-at91
(to accomodate at91sam926x processors) was incomplete. It needs
this patch to be able to build again.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
kernel/built-in.o: In function `pm_suspend':
utsname_sysctl.c:(.text+0x23008): multiple definition of `pm_suspend'
arch/arm/mach-sa1100/built-in.o:arch/arm/mach-sa1100/sleep.S:(.text+0xf68): first defined here
arm-linux-ld: Warning: size of symbol `pm_suspend' changed from 20 in arch/arm/mach-sa1100/built-in.o to 44 in kernel/built-in.o
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CC arch/arm/mach-iop13xx/setup.o
arch/arm/mach-iop13xx/setup.c: In function 'iq8134x_probe_flash_size':
arch/arm/mach-iop13xx/setup.c:210: warning: implicit declaration of function 'ioremap'
arch/arm/mach-iop13xx/setup.c:210: warning: initialization makes pointer from integer without a cast
arch/arm/mach-iop13xx/setup.c:218: warning: implicit declaration of function 'writew'
arch/arm/mach-iop13xx/setup.c:222: warning: implicit declaration of function 'readb'
arch/arm/mach-iop13xx/setup.c:231: warning: implicit declaration of function 'iounmap'
LD .tmp_vmlinux1
arch/arm/mach-iop13xx/built-in.o: In function `iop13xx_platform_init':
iq81340mc.c:(.init.text+0x150): undefined reference to `ioremap'
iq81340mc.c:(.init.text+0x21c): undefined reference to `writew'
iq81340mc.c:(.init.text+0x24c): undefined reference to `writew'
iq81340mc.c:(.init.text+0x254): undefined reference to `iounmap'
iq81340mc.c:(.init.text+0x2c4): undefined reference to `readb'
iq81340mc.c:(.init.text+0x2e8): undefined reference to `readb'
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CC arch/arm/common/sharpsl_pm.o
arch/arm/common/sharpsl_pm.c:30:31: error: asm/apm-emulation.h: No such file or directory
...
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Per device data such as brightness belongs to the indivdual device
and should therefore be separate from the the backlight operation
function pointers. This patch splits the two types of data and
allows simplifcation of some code.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
backlight_device->sem has a very specific use as documented in the
header file. The external users of this are using it for a different
reason, to serialise access to the update_status() method.
backlight users were supposed to implement their own internal
serialisation of update_status() if needed but everyone is doing
things differently and incorrectly. Therefore add a global mutex to
take care of serialisation for everyone, once and for all.
Locking for get_brightness remains optional since most users don't
need it.
Also update the lcd class in a similar way.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>