1. 20 5月, 2010 1 次提交
    • M
      i2c-s3c2410: Remove unconditional 1ms delay on each transfer · 1bc2962e
      Mark Brown 提交于
      The S3C I2C controller indicates completion of I2C transfers before
      the bus has a stop condition on it. In order to ensure that we do not
      attempt to start a new transfer before the bus is idle the driver
      currently inserts a 1ms delay. This is vastly larger than is generally
      required and has a visible effect on performance under load, such as
      when bringing up audio CODECs or reading back status information with
      non-bulk I2C reads.
      
      Replace the sleep with a spin on the IIC status register for up to 1ms.
      This will busy wait but testing on my SMDK6410 system indicates that
      the overwhelming majority of transactions complete on the first spin,
      with maximum latencies of less than 10 spins so the absolute overhead
      of busy waiting should be at worst comprable to msleep(), and the
      overall system performance is dramatically improved.
      
      The main risk is poor interaction with multimaster systems where
      we may miss the bus going idle before the next transaction. Defend
      against this by falling back to the original 1ms delay after 20 spins.
      
      The overall effect in my testing is an approximately 20% improvement
      in kernel startup time.
      Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
      Signed-off-by: NBen Dooks <ben-linux@fluff.org>
      1bc2962e
  2. 04 5月, 2010 3 次提交
  3. 02 5月, 2010 1 次提交
  4. 01 5月, 2010 1 次提交
  5. 20 4月, 2010 5 次提交
    • D
      i2c-stu300: off by one issue · 42df64b1
      Dan Carpenter 提交于
      If we don't find the correct rate, we want to end the loop with "i"
      pointing to the last element in the array.
      Signed-off-by: NDan Carpenter <error27@gmail.com>
      Signed-off-by: NBen Dooks <ben-linux@fluff.org>
      42df64b1
    • K
      i2c-pnx: Add stop conditions for end of transfer · 28ad3321
      Kevin Wells 提交于
      Add a stop condition bit flag to the last byte in the transfer.
      This will generate an extra clock to handle the stop condition
      and prevent devices from staying in an ACK'd state.
      Signed-off-by: NKevin Wells <wellsk40@gmail.com>
      Signed-off-by: NBen Dooks <ben-linux@fluff.org>
      28ad3321
    • K
      i2c-pnx: Limit maximum divider to 1023 · be80dbaa
      Kevin Wells 提交于
      Limit maximum divider to 0x3ff to divider computations. On high I2C
      parent clock rates, the divider can exceed 0x3ff. This will help
      prevent some very odd clock rates.
      Signed-off-by: NKevin Wells <wellsk40@gmail.com>
      Signed-off-by: NBen Dooks <ben-linux@fluff.org>
      be80dbaa
    • M
      i2c-omap: fix OOPS in omap_i2c_unidle() during probe · 7c6bd201
      Mika Westerberg 提交于
      Commit d84d3ea3 added register shift to allow
      also 16-bit register access. However, omap_i2c_unidle() is called before these
      are set which causes the following OOPS:
      
          Unhandled fault: alignment exception (0x801) at 0xfa070009
          Internal error: : 801 [#1]
          last sysfs file:
          Modules linked in:
          CPU: 0    Not tainted  (2.6.34-rc2-00052-gae6be51e #3)
          PC is at omap_i2c_unidle+0x44/0x138
          LR is at trace_hardirqs_on_caller+0x158/0x18c
          pc : [<c01cd2c4>]    lr : [<c00743f8>]    psr: 20000013
          sp : cfc2bf10  ip : 00000009  fp : 00000000
          r10: 00000000  r9 : 00000000  r8 : c0378560
          r7 : c0378b88  r6 : c0378558  r5 : cfcadc00  r4 : cfcadc00
          r3 : 00000009  r2 : fa070000  r1 : 00000000  r0 : 00000000
          Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
          Control: 10c5387f  Table: 80004019  DAC: 00000017
          Process swapper (pid: 1, stack limit = 0xcfc2a2e8)
          Stack: (0xcfc2bf10 to 0xcfc2c000)
          bf00:                                     c0372cf8 c027225c 00000000 c0a69678
          bf20: cfc3e508 c0500898 c0378560 c0378560 c0500898 cfcac8c0 c04fc280 c017d4f4
          bf40: c0378560 c017c63c c0378560 c0378594 c0500898 cfcac8c0 c04fc280 c017c754
          bf60: 00000000 c017c6f4 c0500898 c017beac cfc16a5c cfc3fd94 c0023448 c0500898
          bf80: c0500898 c017b7d4 c032dc7f 00000093 cfc28d40 c0023448 00000000 c0500898
          bfa0: 00000000 00000000 00000000 c017ca48 c0023448 00000000 c001d274 00000000
          bfc0: 00000000 c002b344 00000031 00000000 00000000 00000192 00000000 c0023448
          bfe0: 00000000 00000000 00000000 c0008578 00000000 c002c304 ffdfffff ffffffff
          [<c01cd2c4>] (omap_i2c_unidle+0x44/0x138) from [<c027225c>] (omap_i2c_probe+0x1a4/0x398)
          [<c027225c>] (omap_i2c_probe+0x1a4/0x398) from [<c017d4f4>] (platform_drv_probe+0x18/0x1c)
          [<c017d4f4>] (platform_drv_probe+0x18/0x1c) from [<c017c63c>] (driver_probe_device+0xc0/0x178)
          [<c017c63c>] (driver_probe_device+0xc0/0x178) from [<c017c754>] (__driver_attach+0x60/0x84)
          [<c017c754>] (__driver_attach+0x60/0x84) from [<c017beac>] (bus_for_each_dev+0x44/0x74)
          [<c017beac>] (bus_for_each_dev+0x44/0x74) from [<c017b7d4>] (bus_add_driver+0x9c/0x218)
          [<c017b7d4>] (bus_add_driver+0x9c/0x218) from [<c017ca48>] (driver_register+0xa8/0x130)
          [<c017ca48>] (driver_register+0xa8/0x130) from [<c002b344>] (do_one_initcall+0x5c/0x1b8)
          [<c002b344>] (do_one_initcall+0x5c/0x1b8) from [<c0008578>] (kernel_init+0x90/0x144)
          [<c0008578>] (kernel_init+0x90/0x144) from [<c002c304>] (kernel_thread_exit+0x0/0x8)
          Code: e5942004 e3a0c009 e1a0331c e3a01000 (e18210b3)
          ---[ end trace 1b75b31a2719ed1c ]---
      
      This patch moves register shift setting before any register accesses are done.
      Signed-off-by: NMika Westerberg <ext-mika.1.westerberg@nokia.com>
      Cc: Cory Maccarrone <darkstar6262@gmail.com>
      Signed-off-by: NBen Dooks <ben-linux@fluff.org>
      7c6bd201
    • A
      i2c-imx: fix error handling · da9c99fc
      Arnaud Patard 提交于
      - Return -ETIMEDOUT on bus busy error
      - Fix timeout test "time_after(jiffies, orig_jiffies + HZ / 1000)" :
        By default, HZ=100 on arm. This means that this test has no chances to
        work and may result in a dead loop. Set timeout to 500ms.
      - Don't try to send a new message if we failed to transmit
        previous one. This was preventing to recover from error on my system
      Signed-off-by: NArnaud Patard <apatard@mandriva.com>
      Signed-off-by: NBen Dooks <ben-linux@fluff.org>
      da9c99fc
  6. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  7. 24 3月, 2010 2 次提交
  8. 15 3月, 2010 1 次提交
  9. 14 3月, 2010 6 次提交
  10. 08 3月, 2010 11 次提交
  11. 07 3月, 2010 1 次提交
  12. 02 3月, 2010 7 次提交
    • Z
      i2c: Document the message size limit · 0c43ea54
      Zhangfei Gao 提交于
      i2c_master_send & i2c_master_recv do not support more than 64 kb
      transfer, since msg.len is u16.
      Signed-off-by: NZhangfei Gao <zgao6@marvell.com>
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      0c43ea54
    • J
      i2c-algo-pca: Drop duplicate variable · eec74a25
      Jean Delvare 提交于
      Thanks to -Wshadow.
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      Reviewed-by: NWolfram Sang <w.sang@pengutronix.de>
      eec74a25
    • M
      i2c: Hook up runtime PM support · 6de468ae
      Mark Brown 提交于
      Allow I2C drivers to make use of the runtime PM framework by adding
      bus implementations of the runtime PM operations. These simply
      immediately suspend when the device is idle. The runtime PM framework
      provides drivers with off the shelf refcounts for enables and sysfs
      control for managing runtime suspend from userspace so is useful even
      without meaningful input from the bus.
      Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      6de468ae
    • J
      i2c-parport-light: Add SMBus alert support · 927ab2f8
      Jean Delvare 提交于
      Add support for the SMBus alert mechanism to the i2c-parport-light
      driver. The ADM1032 evaluation board at least is properly wired for
      this.
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      Cc: David Brownell <dbrownell@users.sourceforge.net>
      Cc: Trent Piepho <tpiepho@freescale.com>
      927ab2f8
    • J
      i2c-parport: Add SMBus alert support · 35859254
      Jean Delvare 提交于
      Add support for the SMBus alert mechanism to the i2c-parport driver.
      The ADM1032 evaluation board at least is properly wired for this.
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      Cc: David Brownell <dbrownell@users.sourceforge.net>
      Cc: Trent Piepho <tpiepho@freescale.com>
      35859254
    • J
      i2c: Separate Kconfig option for i2c-smbus · e2ca3074
      Jean Delvare 提交于
      Having a separate Kconfig option for i2c-smbus makes it possible to
      build that support as a module even when i2c-core itself is built-in.
      Bus drivers which implement SMBus alert should select this option, so
      in most cases this option is hidden and the user doesn't have to care
      about it.
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      Cc: David Brownell <dbrownell@users.sourceforge.net>
      Cc: Trent Piepho <tpiepho@freescale.com>
      e2ca3074
    • J
      i2c: Add SMBus alert support · b5527a77
      Jean Delvare 提交于
      SMBus alert support. The SMBus alert protocol allows several SMBus
      slave devices to share a single interrupt pin on the SMBus master,
      while still allowing the master to know which slave triggered the
      interrupt.
      
      This is based on preliminary work by David Brownell. The key
      difference between David's implementation and mine is that his was
      part of i2c-core, while mine is split into a separate, standalone
      module named i2c-smbus. The i2c-smbus module is meant to include
      support for all SMBus extensions to the I2C protocol in the future.
      
      The benefit of this approach is a zero cost for I2C bus segments which
      do not need SMBus alert support. Where David's implementation
      increased the size of struct i2c_adapter by 7% (40 bytes on i386),
      mine doesn't touch it. Where David's implementation added over 150
      lines of code to i2c-core (+10%), mine doesn't touch it. The only
      change that touches all the users of the i2c subsystem is a new
      callback in struct i2c_driver (common to both implementations.) I seem
      to remember Trent was worried about the footprint of David'd
      implementation, hopefully mine addresses the issue.
      Signed-off-by: NJean Delvare <khali@linux-fr.org>
      Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
      Cc: David Brownell <dbrownell@users.sourceforge.net>
      Cc: Trent Piepho <tpiepho@freescale.com>
      b5527a77