i2c-designware: i2c_dw_xfer_msg: Introduce a local "buf" pointer
While we have a local variable "buf_len" for dev->tx_buf_len, we don't
have such local variable for dev->tx_buf pointer. While "buf_len" is
restored at first then updated when we start processing a new i2c_msg
(determined by STATUS_WRITE_IN_PROGRESS flag), ->tx_buf is different.
Such inconsistency makes the code slightly hard to follow.
i2c-designware: Divide i2c_dw_xfer_msg into two functions
We have some steps at the top of i2c_dw_xfer_msg() to set up a slave
address and enable DW I2C core. And it's executed only when we don't
have STATUS_WRITE_IN_PROGRESS.
But we need to make sure that STATUS_WRITE_IN_PROGRESS only indicates
that we have a pending i2c_msg to process. In other words, even if
STATUS_WRITE_IN_PROGRESS is not set, that doesn't mean we're at initial
state in the I2C transaction.
Since i2c_dw_xfer_msg() will be invoked again and again during a
transaction, those init steps have a possibility to be re-processed
needlessly. For example, this issue easily takes place when processing
a combined transaction with a certain condition (the number of tx bytes
in the first i2c_msg, equals to the Tx FIFO depth).
Consequently we should not use STATUS_WRITE_IN_PROGRESS to determine
where we're at in an I2C transaction. It would be better to separate
those initialization steps from i2c_dw_xfer_msg().
Enable RX_FULL interrupt mask by default, and hook it in the interrupt
handler. If requested amount of rx data (defined by IC_RX_TL) is not
available, we don't have to process i2c_dw_read().
As a hardware feature, DW I2C core generates a STOP condition whenever
the Tx FIFO becomes empty (strictly speaking, whenever the last byte in
the Tx FIFO is sent out), even if we have more bytes to be written.
In other words, we must never make "Tx FIFO underrun" happen during
a transaction, except for the last byte. For the safety's sake, we'd
make TX_EMPTY interrupt get triggered every time one byte is processed.
i2c-designware: Process i2c_msg messages in the interrupt handler
Symptom:
--------
When we're going to send/receive the longer size of data than the Tx
FIFO length, the I2C transaction will be divided into several separated
transactions, limited by the Tx FIFO length.
Details:
--------
As a hardware feature, DW I2C core generates a STOP condition whenever
the Tx FIFO becomes empty (strictly speaking, whenever the last byte in
the Tx FIFO is sent out), even if we have more bytes to be written.
Then, once a new transmit data is written to the Tx FIFO, DW I2C core
will initiate a new transaction, which leads to another START condition.
This explains how the transaction in question goes, and implies that
current tasklet-based dw_i2c_pump_msg() strategy couldn't meet the
timing constraint required for avoiding Tx FIFO underrun.
To avoid this scenario, we must keep providing new transmit data within
a given time period. In case of Fast-mode + 32-byte Tx FIFO, for
instance, it takes about 22.5[us] to process single byte, and 720[us] in
total.
This patch removes the existing tasklet-based "pump" system, and move
its jobs into the interrupt handler.
In case a work-in-progress i2c_msg has more bytes to be written, we
need to set STATUS_WRITE_IN_PROGRESS and exit from the msg_write_idx-
searching loop. Otherwise, we will overtake the current msg_write_idx
without waiting for its transmission to be processed.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* Calculate with accurate conditional expressions from DW manuals.
* Round ic_clk by adding 0.5 as it's important at high ic_clk rate.
* Take into account "tHD;STA" issue for _HCNT calculation.
* Take into account "tf" for _LCNT calculation.
* Add "cond" and "offset" fot further correction requirements.
For _HCNT calculation, there's one issue needs to be carefully
considered; DesignWare I2C core doesn't seem to have solid strategy
to meet the tHD;STA timing spec. If you configure _HCNT based on the
tHIGH timing spec, it easily results in violation of the tHD;STA spec.
After many trials, we came to the conclusion that the tHD;STA period
is proportional to (_HCNT + 3). For the safety's sake, this should be
selected by default.
As for _LCNT calculation, DW I2C core has one characteristic behavior;
he starts counting the SCL CNTs for the LOW period of the SCL clock
(tLOW) as soon as it pulls the SCL line. At that time, he doesn't take
into account the fall time of SCL signal (tf), IOW, he starts counting
CNTs without confirming the SCL input voltage has dropped to below VIL.
This characteristics becomes a problem on some platforms where tf is
considerably long, and results in violation of the tLOW timing spec.
To make the driver configurable as much as possible for various cases,
we'd have separated arguments "tf" and "offset", and for safety default
values should be 0.3 us and 0, respectively.
i2c-designware: Consolidate to use 32-bit word accesses
This driver looks originally meant for armel machines where readw()/
writew() works perfectly fine with this hardware. But that doens't
work for big-endian systems.
This patch converts all 8/16-bit-aware usages to 32-bit variants.
Linus Torvalds [Tue, 8 Dec 2009 16:19:16 +0000 (08:19 -0800)]
Merge branch 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block: (113 commits)
cfq-iosched: Do not access cfqq after freeing it
block: include linux/err.h to use ERR_PTR
cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit
blkio: Allow CFQ group IO scheduling even when CFQ is a module
blkio: Implement dynamic io controlling policy registration
blkio: Export some symbols from blkio as its user CFQ can be a module
block: Fix io_context leak after failure of clone with CLONE_IO
block: Fix io_context leak after clone with CLONE_IO
cfq-iosched: make nonrot check logic consistent
io controller: quick fix for blk-cgroup and modular CFQ
cfq-iosched: move IO controller declerations to a header file
cfq-iosched: fix compile problem with !CONFIG_CGROUP
blkio: Documentation
blkio: Wait on sync-noidle queue even if rq_noidle = 1
blkio: Implement group_isolation tunable
blkio: Determine async workload length based on total number of queues
blkio: Wait for cfq queue to get backlogged if group is empty
blkio: Propagate cgroup weight updation to cfq groups
blkio: Drop the reference to queue once the task changes cgroup
blkio: Provide some isolation between groups
...
Linus Torvalds [Tue, 8 Dec 2009 16:18:01 +0000 (08:18 -0800)]
Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (54 commits)
Revert "pata_sis: Implement MWDMA for the UDMA 133 capable chips"
libata: Clarify ata_set_lba_range_entries function
libata: Report zeroed read after TRIM and max discard size
pata_hpt3x2n: fix overclocked MWDMA0 timing
pata_it8213: MWDMA0 is unsupported
[libata] MWDMA0 is unsupported on PIIX-like PATA controllers
pata_via: clear UDMA transfer mode bit for PIO and MWDMA
pata_sis: Power Management fix
pata_rz1000: Power Management fix
pata_radisys: fix UDMA handling
pata_ns87415: Power Management fix
pata_marvell: fix marvell_pre_reset() documentation
pata_legacy: add pointers to QDI65x0 documentation
pata_legacy: fix access to control register for QDI6580
pata_legacy: fix QDI6580DP support
pata_it8213: fix it8213_pre_reset() documentation
pata_it8213: fix wrong MWDMA timings being programmed
pata_it8213: fix PIO2 underclocking
pata_it8213: fix wrong PIO timings being programmed
pata_it8213: fix UDMA handling
...
Linus Torvalds [Tue, 8 Dec 2009 16:13:35 +0000 (08:13 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: parport_mfc3 - Not makes it a bool before the comparison.
m68k: don't export static inline functions
fbdev: atafb - add palette register check
m68k: Remove the BKL from sys_execve
m68k: Cleanup linker scripts using new linker script macros.
m68k: Make thread_info.h usable from assembly.
m68knommu: define arch_has_single_step() and friends
m68k: ptrace fixes
m68k: use generic code for ptrace requests
rtc: Add an RTC driver for the Ricoh RP5C01
rtc: Add an RTC driver for the Oki MSM6242
Linus Torvalds [Tue, 8 Dec 2009 16:12:16 +0000 (08:12 -0800)]
Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c-stub: Documentation update
i2c-stub: Allow user to disable some commands
i2c-stub: Implement I2C block support
i2c: Refactor for_each callbacks
i2c-i801: Retry on lost arbitration
i2c: Remove big kernel lock from i2cdev_open
ics932s401: Clean up detect function
i2c: Simplify i2c_detect_address
i2c: Drop probe, ignore and force module parameters
i2c: Add missing __devinit markers to old i2c adapter drivers
i2c: Bus drivers don't have to support I2C_M_REV_DIR_ADDR
i2c: Prevent priority inversion on top of bus lock
i2c-voodoo3: Delete
i2c-powermac: Drop temporary name buffer
i2c-powermac: Include the i2c_adapter in struct pmac_i2c_bus
i2c-powermac: Log errors
i2c-powermac: Refactor i2c_powermac_smbus_xfer
i2c-powermac: Reject unsupported I2C transactions
i2c/chips: Move ds1682 to drivers/misc
Linus Torvalds [Tue, 8 Dec 2009 16:07:16 +0000 (08:07 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM: Add flag for devices capable of generating run-time wake-up events
PM / Runtime: Remove unnecessary braces in __pm_runtime_set_status()
PM / Runtime: Make documentation of runtime_idle() agree with the code
PM / Runtime: Ensure timer_expires is nonzero in pm_schedule_suspend()
PM / Runtime: Use deferred_resume flag in pm_request_resume
PM / Runtime: Export the PM runtime workqueue
PM / Runtime: Fix lockdep warning in __pm_runtime_set_status()
PM / Hibernate: Swap, use KERN_CONT
PM / Hibernate: Shift remaining code from swsusp.c to hibernate.c
PM / Hibernate: Move swap functions to kernel/power/swap.c.
PM / freezer: Don't get over-anxious while waiting
Linus Torvalds [Tue, 8 Dec 2009 16:02:38 +0000 (08:02 -0800)]
Merge branch 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (84 commits)
KVM: VMX: Fix comparison of guest efer with stale host value
KVM: s390: Fix prefix register checking in arch/s390/kvm/sigp.c
KVM: Drop user return notifier when disabling virtualization on a cpu
KVM: VMX: Disable unrestricted guest when EPT disabled
KVM: x86 emulator: limit instructions to 15 bytes
KVM: s390: Make psw available on all exits, not just a subset
KVM: x86: Add KVM_GET/SET_VCPU_EVENTS
KVM: VMX: Report unexpected simultaneous exceptions as internal errors
KVM: Allow internal errors reported to userspace to carry extra data
KVM: Reorder IOCTLs in main kvm.h
KVM: x86: Polish exception injection via KVM_SET_GUEST_DEBUG
KVM: only clear irq_source_id if irqchip is present
KVM: x86: disallow KVM_{SET,GET}_LAPIC without allocated in-kernel lapic
KVM: x86: disallow multiple KVM_CREATE_IRQCHIP
KVM: VMX: Remove vmx->msr_offset_efer
KVM: MMU: update invlpg handler comment
KVM: VMX: move CR3/PDPTR update to vmx_set_cr3
KVM: remove duplicated task_switch check
KVM: powerpc: Fix BUILD_BUG_ON condition
KVM: VMX: Use shared msr infrastructure
...
Trivial conflicts due to new Kconfig options in arch/Kconfig and kernel/Makefile
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1815 commits)
mac80211: fix reorder buffer release
iwmc3200wifi: Enable wimax core through module parameter
iwmc3200wifi: Add wifi-wimax coexistence mode as a module parameter
iwmc3200wifi: Coex table command does not expect a response
iwmc3200wifi: Update wiwi priority table
iwlwifi: driver version track kernel version
iwlwifi: indicate uCode type when fail dump error/event log
iwl3945: remove duplicated event logging code
b43: fix two warnings
ipw2100: fix rebooting hang with driver loaded
cfg80211: indent regulatory messages with spaces
iwmc3200wifi: fix NULL pointer dereference in pmkid update
mac80211: Fix TX status reporting for injected data frames
ath9k: enable 2GHz band only if the device supports it
airo: Fix integer overflow warning
rt2x00: Fix padding bug on L2PAD devices.
WE: Fix set events not propagated
b43legacy: avoid PPC fault during resume
b43: avoid PPC fault during resume
tcp: fix a timewait refcnt race
...
Fix up conflicts due to sysctl cleanups (dead sysctl_check code and
CTL_UNNUMBERED removed) in
kernel/sysctl_check.c
net/ipv4/sysctl_net_ipv4.c
net/ipv6/addrconf.c
net/sctp/sysctl.c
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next-2.6:
sparc: Set UTS_MACHINE correctly.
sparc,leon: init_leon srmmu cleanup
sparc32: Remove early interrupt enable.
sparc, leon: Added Aeroflex Gaisler entry in manufacturer_info structure
sparc64: Faster early-boot framebuffer console.
Revert "sparc: Make atomic locks raw"
sparc: remove unused nfsd #includes
sparc: Fixup last users of irq_chip->typename
Added sparc_leon3_snooping_enabled() and converted extern inline to static inline
No auxio on LEON
apbuart: Use of_find_node_by_path to find root node.
sparc: Replace old style lock initializer
sparc: Make atomic locks raw
apbuart: Fix build and missing driver unregister.
apbuart: Kill dependency on deprecated Sparc-only PROM interfaces.
apbuart: Fix build warning.
sparc: Support for GRLIB APBUART serial port
watchdog: Remove BKL from rio watchdog driver
sparc: Remove BKL from apc
sparc,leon: Sparc-Leon SMP support
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits)
security/tomoyo: Remove now unnecessary handling of security_sysctl.
security/tomoyo: Add a special case to handle accesses through the internal proc mount.
sysctl: Drop & in front of every proc_handler.
sysctl: Remove CTL_NONE and CTL_UNNUMBERED
sysctl: kill dead ctl_handler definitions.
sysctl: Remove the last of the generic binary sysctl support
sysctl net: Remove unused binary sysctl code
sysctl security/tomoyo: Don't look at ctl_name
sysctl arm: Remove binary sysctl support
sysctl x86: Remove dead binary sysctl support
sysctl sh: Remove dead binary sysctl support
sysctl powerpc: Remove dead binary sysctl support
sysctl ia64: Remove dead binary sysctl support
sysctl s390: Remove dead sysctl binary support
sysctl frv: Remove dead binary sysctl support
sysctl mips/lasat: Remove dead binary sysctl support
sysctl drivers: Remove dead binary sysctl support
sysctl crypto: Remove dead binary sysctl support
sysctl security/keys: Remove dead binary sysctl support
sysctl kernel: Remove binary sysctl logic
...
Sergei Shtylyov notes "You call min() on uncomparables [in
mwdma_clip_to_pio()], i.e. mwdma_to_pio[] contains XFER_PIO_* and
adev->pio_mode - XFER_PIO_0 yields you a mode number. Thus the second
argument will always "win" as a minimal one"
Bartlomiej Zolnierkiewicz adds "There are more issues with the patch related
to mwdma_clip_to_pio(). The function can return values between 0 and
4 which obviously won't work well for the new code below for values
>2 (i.e. resulting in out-of-bounds array access for the common-case
of dev->pio_mode == XFER_PIO_4)."
Bartlomiej Zolnierkiewicz also notes the patch is incomplete, failing to
update MWDMA mode masks.
Many features of h3100/h3600 (LCD, PCMCIA, Flash write, etc.)
depend on correct functioning of GPIO expander handled by htc-egpio
driver, so force its building in Kconfig.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Dmitry Artamonow [Fri, 27 Nov 2009 11:13:01 +0000 (12:13 +0100)]
ARM: 5823/1: SA1100: h3100/h3600: add support for gpio-keys
Add support for "Power" and "Action" (joystick center) buttons -
the only buttons on iPaq h3100/h3600 connected to GPIOs
(other buttons are controlled by microcontroller)
Also remove setting PWER for wakeup on Power button press -
gpio-keys driver will handle it.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Correct boilerplates after files split. Also shorten them a bit - use
standart GPL wording (as per http://lkml.org/lkml/2007/5/1/220) and
drop changelog, which only entry about h3800 support and abstracted
EGPIOs is just confusing now, as both of these features are gone.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Dmitry Artamonow [Fri, 27 Nov 2009 11:10:55 +0000 (12:10 +0100)]
ARM: 5820/1: SA1100: h3100/h3600: split h3600.c
Split common h3600.c into three separate files: h3100.c, h3600.c and
h3xxx.c (the latter contains common code for h3100/h3600)
Copyright boilerplates and #includes are copied intact and will be
cleaned up later.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Dmitry Artamonow [Fri, 27 Nov 2009 11:07:47 +0000 (12:07 +0100)]
ARM: 5818/1: SA1100: h3100/h3600: drop old GPIO definitions
As all existing code was converted to gpiolib, drop no more
used pre-gpiolib (bit-shifted) GPIO definintions.
Supply new gpiolib-friendly definitions for GPIOs which
don't have them yet.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Dmitry Artamonow [Fri, 27 Nov 2009 11:07:11 +0000 (12:07 +0100)]
ARM: 5817/1: SA1100: h3100/h3600: configure all unused gpios as inputs
After conversion to gpiolib there's still some GPIOs left, that get
configured in *_mach_init() as outputs (using direct operations
on GPCR/GPDR registers), but otherwise unused. These GPIOs are mainly
sound related and should be configured by corresponding driver once
it is written.
Drop this initialisation and configure all GPIOs as input.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Dmitry Artamonow [Fri, 27 Nov 2009 11:02:28 +0000 (12:02 +0100)]
ARM: 5814/1: SA1100: h3100/h3600: convert all users of assign_h3600_egpio to gpiolib
Use of gpio_request/gpio_free in some callbacks may look ugly, but
corresponding drivers (sa1100_serial and sa1100_fb) don't provide (yet)
init/exit hooks and registering these gpios in *_mach_init is also
not possible, because htc-gpio driver starts a bit later...
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Dmitry Artamonow [Fri, 27 Nov 2009 10:58:35 +0000 (11:58 +0100)]
ARM: 5812/1: SA1100: h3100/h3600: separate machine-specific LCD helpers
h3100 and h3600 have different sets of LCD-controlling gpios,
which mapped to the same "abstracted" EGPIO.
As we plan to get rid of those abstracted egpios completely, we
need to separate these helper functions.
Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Jean Delvare [Sun, 6 Dec 2009 16:06:29 +0000 (17:06 +0100)]
i2c-stub: Allow user to disable some commands
Add a module parameter to override the functionality bitfield. This
lets the user disable some commands. This can be used to force a chip
driver to take different code paths.
Jean Delvare [Sun, 6 Dec 2009 16:06:27 +0000 (17:06 +0100)]
i2c: Refactor for_each callbacks
Functions i2c_do_add_adapter() and __attach_adapter() do essentially
the same thing, differing only in how the parameters are passed. Same
for i2c_do_add_adapter() and __detach_adapter(). Introduce wrappers to
normalize the parameters, so that we do not have to duplicate the
code.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
Jean Delvare [Sun, 6 Dec 2009 16:06:27 +0000 (17:06 +0100)]
i2c-i801: Retry on lost arbitration
The Intel 82801 is sometimes used on systems with a BMC connected. The
BMC can access the SMBus, resulting in lost arbitration for the 82801.
We should let i2c-core retry transactions for us in this case.
Vincent Sanders [Sun, 6 Dec 2009 16:06:26 +0000 (17:06 +0100)]
i2c: Remove big kernel lock from i2cdev_open
The BKL is held over a kmalloc so cannot protect anything beyond that.
The two calls before the kmalloc have their own locking.
Improve device open function by removing the now unnecessary ret variable
Signed-off-by: Vincent Sanders <vince@simtec.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Jean Delvare [Sun, 6 Dec 2009 16:06:24 +0000 (17:06 +0100)]
i2c: Drop probe, ignore and force module parameters
The legacy probe and force module parameters are obsolete now, the
same can be achieved using the new_device sysfs interface, which is
both more flexible and cheaper (it is implemented by i2c-core rather
than replicated in every driver module.)
The legacy ignore module parameters can be dropped as well. Ignoring
can be done by instantiating a "dummy" device at the problematic
address.
This is the first step of a huge cleanup to i2c-core's i2c_detect
function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made
use of them.
Jean Delvare [Sun, 6 Dec 2009 16:06:22 +0000 (17:06 +0100)]
i2c: Bus drivers don't have to support I2C_M_REV_DIR_ADDR
I2C bus drivers don't have to support I2C_M_REV_DIR_ADDR. It is a
deviation from the I2C specification, which only makes sense to
implement when really needed.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Ben Dooks <ben-linux@fluff.org>
Mika Kuoppala [Sun, 6 Dec 2009 16:06:22 +0000 (17:06 +0100)]
i2c: Prevent priority inversion on top of bus lock
Low priority thread holding the i2c bus mutex could block higher
priority threads to access the bus resulting in unacceptable
latencies. Change the mutex type to rt_mutex preventing priority
inversion.
Tested-by: Peter Ujfalusi <peter.ujfalusi@nokia.com> Signed-off-by: Mika Kuoppala <mika.kuoppala@nokia.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Jean Delvare [Sun, 6 Dec 2009 16:06:18 +0000 (17:06 +0100)]
i2c-powermac: Log errors
Log errors when they happen, otherwise we have no idea what went
wrong.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Michel Daenzer <michel@daenzer.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org>
Jean Delvare [Sun, 6 Dec 2009 16:06:17 +0000 (17:06 +0100)]
i2c-powermac: Refactor i2c_powermac_smbus_xfer
I wanted to add some error logging to the i2c-powermac driver, but
found that it was very difficult due to the way the
i2c_powermac_smbus_xfer function is organized. Refactor the code in
this function so that each low-level function is only called once.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Michel Daenzer <michel@daenzer.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org>
Jean Delvare [Sun, 6 Dec 2009 16:06:17 +0000 (17:06 +0100)]
i2c-powermac: Reject unsupported I2C transactions
The i2c-powermac driver doesn't support arbitrary multi-message I2C
transactions, only SMBus ones. Make it clear by returning an error if
a multi-message I2C transaction is attempted. This is better than only
processing the first message, because most callers won't recover from
the short transaction. Anyone wishing to issue multi-message
transactions should use the SMBus API instead of the raw I2C API.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Michel Daenzer <michel@daenzer.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org>
Wolfram Sang [Sun, 6 Dec 2009 16:06:16 +0000 (17:06 +0100)]
i2c/chips: Move ds1682 to drivers/misc
As i2c/chips is deprecated, move ds1682 to a more apropriate location.
Build tested.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Jean Delvare <khali@linux-fr.org>
PM: Add flag for devices capable of generating run-time wake-up events
Apparently, there are devices that can wake up the system from sleep
states and yet are incapable of generating wake-up events at run
time. Thus, introduce a flag indicating if given device is capable
of generating run-time wake-up events.
PM / Runtime: Make documentation of runtime_idle() agree with the code
Currently the ->runtime_idle() callback is documented as having no
return value, but in fact it returns int. Although its return value
is ignored at the PM core level, it may be used by bus type routines
executing the drivers' ->runtime_idle() callbacks.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Alan Stern <stern@rowland.harvard.edu>
PM / Runtime: Ensure timer_expires is nonzero in pm_schedule_suspend()
The runtime PM core code assumes that dev->power.timer_expires is
nonzero when the timer is scheduled, but it may become zero
incidentally in pm_schedule_suspend(). Prevent this from happening
by bumping dev->power.timer_expires up to 1 if it's 0 before calling
mod_timer().
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Alan Stern <stern@rowland.harvard.edu>
Alan Stern [Thu, 3 Dec 2009 19:22:34 +0000 (20:22 +0100)]
PM / Runtime: Use deferred_resume flag in pm_request_resume
This patch (as1307) adds a small optimization to
__pm_request_resume(). If the device is currently being suspended,
there's no need to queue a work routine to resume it. Setting the
deferred_resume flag will suffice. (There's also a minor improvement
to the function's code layout: An unnecessary "else" is removed.)
Also, the patch clarifies the usage of the deferred_resume flag. It
is meaningful only while a suspend is in progress, so it should be
cleared just before a suspend starts, not just after one ends.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tim Abbott [Sun, 27 Sep 2009 17:57:55 +0000 (13:57 -0400)]
m68k: Cleanup linker scripts using new linker script macros.
Signed-off-by: Tim Abbott <tabbott@ksplice.com> Tested-by: Andreas Schwab <schwab@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
m68knommu: define arch_has_single_step() and friends
Towards adding CONFIG_UTRACE support for non-mmu m68k add
arch_has_single_step, and its support functions user_enable_single_step()
and user_disable_single_step().
[Geert] m68k conflict resolution from linux-next
Jens Axboe [Sun, 6 Dec 2009 08:54:19 +0000 (09:54 +0100)]
cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit
After the merge of the IO controller patches, booting on my megaraid
box ran much slower. Vivek Goyal traced it down to megaraid discovery
creating tons of devices, each suffering a grace period when they later
kill that queue (if no device is found).
So lets use call_rcu() to batch these deferred frees, instead of taking
the grace period hit for each one.
projects / linux-beck.git / log