When I2C block reads are not supported by the underlying adapter, use
SMBus read word transactions instead of consecutive byte reads.
Reasons for this change are:
* The consecutive byte read approach is not safe on multi-master buses.
* While consecutive byte reads have less overhead if you only count the
bytes on the bus, it takes more than twice as many transactions as
with SMBus read word transactions, and each transaction has a cost:
taking and releasing the adapter mutex, and for polling drivers,
waiting for the transaction to complete.
This change yields a significant performance boost at HZ=250 with
EEPROMs on an Intel 82801 bus (basically twice as fast.)
SMBus read word transactions are widely supported so I don't expect
compatibility issues.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.
Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.
So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Let framebuffer drivers set their I2C bus class to DDC. Once this is
done, we will be able to tell the eeprom driver to only probe for
EDID EEPROMs on these buses.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Bugfixes to the i2c-cpm driver
- enable correct interrupts (I2CER_TXE instead of I2CER_BUSY)
- replace forgotten iic with i2c
- prefix debug-output on init with 0x and add frequency
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This driver uses the port of 2.4 code from Vitaly Bordug
<vitb@kernel.crashing.org> and the actual algorithm used by the i2c
driver of the DBox code on cvs.tuxboc.org from Felix Domke
(tmbinc@gmx.net) and Gillem (htoa@gmx.net) converted to an
of_platform_driver. Tested on CPM1 (MPC823 on dbox2 hardware) and
CPM2 (MPC8272).
Signed-off-by: Jochen Friedrich <jochen@scram.de>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This is part of the effort to get rid of the BKL.
[JD: In fact i2c-dev doesn't need more locking than is already done
for the other i2c drivers, so we can simply switch to unlocked_ioctl.]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
New i2c bus driver for the Intel SCH chipsets (AF82US15W, AF82US15L,
AF82UL11L).
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Use list_for_each_entry_safe() in i2c_del_adapter() and i2c_del_driver().
Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Fix errorcode to be more descriptive when ioremap fails.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Give a more concrete error code, when the bus is not idle.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Many PC SMBus host controller drivers don't properly handle the case
where they are requested to achieve a transaction they do not support.
Update them so that the consistently print a warning message and
return a single error value in this case.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The i2c-piix4 driver was used recently as a model to write a new SMBus
host controller driver and this made me realize that the code of this
old driver wasn't exactly good. So, here are many cleanups and minor
fixes to this driver, so that these minor mistakes aren't duplicated
again:
* Delete unused structure.
* Delete needless forward function declaration.
* Properly announce the SMBus host controller as we find it.
* Spell it SMBus not SMB.
* Return -EBUSY instead of -ENODEV when the I/O region is already in
use.
* Drop useless masks on the 7-bit address and the R/W bit.
* Reject block transaction requests with an invalid block length.
* Check and report block transaction replies with an invalid block
length.
* Delete a useless comment.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tighten error paths used by various i2c adapters (mostly x86) so
they return real fault/errno codes instead of a "-1" (which is
most often interpreted as "-EPERM"). Build tested, with eyeball
review.
One minor initial goal is to have adapters consistently return
the code "-ENXIO" when addressing a device doesn't get an ACK
response, at least in the probe paths where they are already
good at stifling related logspam.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Defend the i2c refcount calls against NULL pointers, as is important
(and conventional) for such calls. Note that none of the current
callers of i2c_use_client() use its return value.
[JD: I hate this but apparently all the other subsystems do it so...]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Provide kerneldoc for most of the I2C and SMBus I/O calls. Add a
comment summarizing some fault reporting issues which affect the
ability to provide clean fault reports through I2C master transfer
calls. (Making it hard to precisely specify their return values...)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Function i2c_smbus_write_quick has no users left, so we can delete it.
Also update the list of these helper functions which are gone but
could be added back if needed.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The list of I2C/SMBus bus drivers is growing and it is sometimes
difficult for the users to figure out what drivers they should enable.
By grouping the drivers by type, I hope to make the selection easier.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
More updates to the I2C stack's fault reporting: make the core stop
returning "-1" (usually "-EPERM") for all faults. Instead, pass lower
level fault code up the stack, or return some appropriate errno.
This patch happens to touch almost exclusively SMBus calls.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Since only a few Blackfins lack TWI, just list them in a depends
statement.
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This patch contains the scheduled removal of i2c-i810, i2c-prosavage
and i2c-savage4.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Just like the Tyan S4882, the S4985 uses a multiplexer to give access
to all 16 memory module SPD EEPROMs. This specific i2c-nforce2-s4985
driver adds support for this. It is heavily based on the older
i2c-amd756-s4882 driver.
As more mainboards will use multiplexer chips, we will have to find a
way to support them without having to write a new specfic driver for
each. The recent changes to the i2c subsystem should help us, and the
new gpio subsystem might help, too.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
If an interrupt happens before an I2c master read/write,
complete is called on uninitialized structure.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
If wait_for_completion_interruptible_timeout exits due
to a signal, the i2c bus was locking up.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Interrupts are enabled at the point where the DAVINCI_I2C_IVR_REG is read,
so unless an interrupt happened just at that moment, no interrupt would be
pending. Even though documentation implies you should do this, I see no
reason. If slave support is added, this read would cause a hard to
reproduce bug.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Previously the dev_dbg only printed if no error.
Printing also on an error is more useful
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Ensure psc value gives a clock between 7-12 MHz
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
[SCSI] bsg: fix oops on remove
[SCSI] fusion: default MSI to disabled for SPI and FC controllers
[SCSI] ipr: Fix HDIO_GET_IDENTITY oops for SATA devices
[SCSI] mptspi: fix oops in mptspi_dv_renegotiate_work()
[SCSI] erase invalid data returned by device
Cortland Setlow pointed out a bug in ov7670.c where the result from
ov7670_read() was just being checked for !0, rather than <0. This made me
realize that ov7670_read's semantics were rather confusing; it both fills
in 'value' with the result, and returns it. This is goes against general
kernel convention; so rather than fixing callers, let's fix the function.
This makes ov7670_read return <0 in the case of an error, and 0 upon
success. Thus, code like:
res = ov7670_read(...);
if (!res)
goto error;
..will work properly.
Signed-off-by: Cortland Setlow <csetlow@tower-research.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I had 8250.nr_uarts=16 in the boot line of a test kernel and I had a weird
mysterious crash in sysfs. After taking an in-depth look I realized that
CONFIG_SERIAL_8250_NR_UARTS was set to 4 and I was walking off the end of
the serial8250_ports array.
Ouch!!!
Don't let this happen to someone else.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is a bugfix for how defio handles multiple processes manipulating
the same framebuffer.
Thanks to Bernard Blackham for identifying this bug.
It occurs when two applications mmap the same framebuffer and concurrently
write to the same page. Normally, this doesn't occur since only a single
process mmaps the framebuffer. The symptom of the bug is that the mapping
applications will hang. The cause is that defio incorrectly tries to add the
same page twice to the pagelist. The solution I have is to walk the pagelist
and check for a duplicate before adding. Since I needed to walk the pagelist,
I now also keep the pagelist in sorted order.
Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Bernard Blackham <bernard@largestprime.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Coverity CID: 1356 RESOURCE_LEAK
I found a very old patch for this that was Acked but did not get applied
https://lists.linux-foundation.org/pipermail/kernel-janitors/2006-September/016362.html
There looks to be a small leak in isdn_writebuf_stub() in isdn_common.c, when
copy_from_user() returns an un-copied data length (length != 0). The below
patch should be a minimally invasive fix.
Signed-off-by: Darren Jenkins <darrenrjenkins@gmailcom>
Acked-by: Karsten Keil <kkeil@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Coverity CID: 2172 RESOURCE_LEAK
When pool_allocate() tries to enlarge a packet, if it can not allocate enough
memory, it returns NULL without first freeing the old packet.
This patch just frees the packet first.
Signed-off-by: Darren Jenkins <darrenrjenkins@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a fault on the FC controllers that makes them not respond
correctly to MSI. The SPI controllers are fine, but are likely to be
onboard on older motherboards which don't handle MSI correctly, so
default both these cases to disabled. Enable by setting the module
parameter mpt_msi_enable=1.
For the SAS case, enable MSI by default, but it can be disabled by
setting the module parameter mpt_msi_enable=0.
Cc: "Prakash, Sathya" <sathya.prakash@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch corrects the handling of write operations to the IPMI watchdog
to work as intended by returning the number of characters actually
processed. Without this patch, an "echo V >/dev/watchdog" enables the
watchdog if IPMI is providing the watchdog function.
Signed-off-by: Mark Rustad <MRustad@gmail.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Currently, ipr does not support HDIO_GET_IDENTITY to SATA devices.
An oops occurs if userspace attempts to send the command. Since hald
issues the command, ensure we fail the ioctl in ipr. This is a
temporary solution to the oops. Once the ipr libata EH conversion
is upstream, ipr will fully support HDIO_GET_IDENTITY.
Tested-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
libata-acpi: don't call sleeping function from invalid context
Added Targa Visionary 1000 IDE adapter to pata_sis.c
libata-acpi: filter out DIPM enable
The problem is introduced by commit
664d080c41.
acpi_evaluate_integer is a sleeping function,
and it should not be called with spin_lock_irqsave.
https://bugzilla.redhat.com/show_bug.cgi?id=451399
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Some BIOSen enable DIPM via _GTF which causes command timeouts under
certain configuration. This didn't occur on 2.6.25 because 2.6.25
defaulted to SRST, so _GTF wasn't executed during boot probe, so ahci
host reset disabled DIPM and as _GTF wasn't executed after SRST, DIPM
wasn't enabled. On 2.6.26, hardreset is used during probe and after
probe _GTF is executed enabling DIPM and thus the failures.
This patch could theoretically disable DIPM on machines which used to
have it enabled on 2.6.25 but AFAIK ahci is currently the only driver
which uses SATA ACPI hierarchy (_SDD) and as the host reset would have
always disabled DIPM, this shouldn't happen.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The IRQ rate reported back by the RTC is incorrect when HPET is enabled.
Newer hardware that has HPET to emulate the legacy RTC device gets this value
wrong since after it sets the rate, it returns before setting the variable
used to report the IRQ rate back to users of the device -- so the set rate and
the reported rate get out of sync.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Brownell <david-b@pacbell.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
