23 Nov, 2011

1 commit


14 Nov, 2011

1 commit

  • I assumed all PCI buses had a bridge, but playing with qemu recently, I
    discovered vgaarb bug where it wasn't detecting both devices shared a bridge
    at the root level.

    Don't check for NULL, if two buses have a NULL bridge, assume they share the
    root bus.

    Acked-by: Jesse Barnes
    Signed-off-by: Dave Airlie

    Dave Airlie
     

26 Jul, 2011

1 commit


25 May, 2011

1 commit

  • * 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (169 commits)
    drivers/gpu/drm/radeon/atom.c: fix warning
    drm/radeon/kms: bump kms version number
    drm/radeon/kms: properly set num banks for fusion asics
    drm/radeon/kms/atom: move dig phy init out of modesetting
    drm/radeon/kms/cayman: fix typo in register mask
    drm/radeon/kms: fix typo in spread spectrum code
    drm/radeon/kms: fix tile_config value reported to userspace on cayman.
    drm/radeon/kms: fix incorrect comparison in cayman setup code.
    drm/radeon/kms: add wait idle ioctl for eg->cayman
    drm/radeon/cayman: setup hdp to invalidate and flush when asked
    drm/radeon/evergreen/btc/fusion: setup hdp to invalidate and flush when asked
    agp/uninorth: Fix lockups with radeon KMS and >1x.
    drm/radeon/kms: the SS_Id field in the LCD table if for LVDS only
    drm/radeon/kms: properly set the CLK_REF bit for DCE3 devices
    drm/radeon/kms: fixup eDP connector handling
    drm/radeon/kms: bail early for eDP in hotplug callback
    drm/radeon/kms: simplify hotplug handler logic
    drm/radeon/kms: rewrite DP handling
    drm/radeon/kms/atom: add support for setting DP panel mode
    drm/radeon/kms: atombios.h updates for DP panel mode
    ...

    Linus Torvalds
     

16 May, 2011

1 commit

  • If the requested device is already active, ignore the request.

    This restores the original behaviour of the interface. The change was
    probably an unintended side effect of

    commit 66b37c6777c4 vga_switcheroo: split switching into two stages

    which did not take into account to duplicate the !active check in the split-off
    stage2.

    Fix this by factoring that check out of stage1 into the debugfs_write routine.

    References: https://bugzilla.kernel.org/show_bug.cgi?id=34252
    Reported-by: Igor Murzov
    Tested-by: Igor Murzov
    Signed-off-by: Florian Mickler
    Signed-off-by: Dave Airlie

    Florian Mickler
     

04 May, 2011

2 commits

  • So in a lot of modern systems, a GPU will always be below a parent bridge that won't share with any other GPUs. This means VGA arbitration on those GPUs can be controlled by using the bridge routing instead of io/mem decodes.

    The problem is locating which GPUs share which upstream bridges. This patch attempts to identify all the GPUs which can be controlled via bridges, and ones that can't. This patch endeavours to work out the bridge sharing semantics.

    When disabling GPUs via a bridge, it doesn't do irq callbacks or touch the io/mem decodes for the gpu.

    Signed-off-by: Dave Airlie

    Dave Airlie
     
  • This is unbalanced and probably more fitting for the client
    to take care of. Remove it.

    Signed-off-by: Alex Williamson
    Signed-off-by: Dave Airlie

    Alex Williamson
     

31 Mar, 2011

1 commit


25 Jan, 2011

1 commit


23 Jan, 2011

1 commit

  • Starting with SandyBridge (though possible with earlier hacked BIOSes),
    the BIOS may initialise the IGFX as secondary to a discrete GPU. Prior,
    it would simply disable the integrated GPU. So we adjust our PCI class
    mask to match any DISPLAY_CLASS device.

    In such a configuration, the IGFX is not a primary VGA controller and
    so should not take part in VGA arbitration, and the error return from
    vga_client_register() is expected.

    Signed-off-by: Chris Wilson
    Cc: stable@kernel.org

    Chris Wilson
     

21 Jan, 2011

1 commit

  • The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
    is used to configure any non-standard kernel with a much larger scope than
    only small devices.

    This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
    references to the option throughout the kernel. A new CONFIG_EMBEDDED
    option is added that automatically selects CONFIG_EXPERT when enabled and
    can be used in the future to isolate options that should only be
    considered for embedded systems (RISC architectures, SLOB, etc).

    Calling the option "EXPERT" more accurately represents its intention: only
    expert users who understand the impact of the configuration changes they
    are making should enable it.

    Reviewed-by: Ingo Molnar
    Acked-by: David Woodhouse
    Signed-off-by: David Rientjes
    Cc: Greg KH
    Cc: "David S. Miller"
    Cc: Jens Axboe
    Cc: Arnd Bergmann
    Cc: Robin Holt
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Rientjes
     

07 Jan, 2011

1 commit


05 Jan, 2011

5 commits


23 Oct, 2010

1 commit

  • * 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
    vfs: make no_llseek the default
    vfs: don't use BKL in default_llseek
    llseek: automatically add .llseek fop
    libfs: use generic_file_llseek for simple_attr
    mac80211: disallow seeks in minstrel debug code
    lirc: make chardev nonseekable
    viotape: use noop_llseek
    raw: use explicit llseek file operations
    ibmasmfs: use generic_file_llseek
    spufs: use llseek in all file operations
    arm/omap: use generic_file_llseek in iommu_debug
    lkdtm: use generic_file_llseek in debugfs
    net/wireless: use generic_file_llseek in debugfs
    drm: use noop_llseek

    Linus Torvalds
     

15 Oct, 2010

1 commit

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     

24 Sep, 2010

1 commit

  • Correct function being needlessly visible outside compilation unit
    when the only users are internal.

    Signed-off-by: Daniel J Blueman
    Reviewed-by: Alex Deucher
    Signed-off-by: Dave Airlie

    Daniel J Blueman
     

03 Jun, 2010

2 commits


19 May, 2010

1 commit

  • * anholt/drm-intel-next: (515 commits)
    drm/i915: Fix out of tree builds
    drm/i915: move fence lru to struct drm_i915_fence_reg
    drm/i915: don't allow tiling changes on pinned buffers v2
    drm/i915: Be extra careful about A/D matching for multifunction SDVO
    drm/i915: Fix DDC bus selection for multifunction SDVO
    drm/i915: cleanup mode setting before unmapping registers
    drm/i915: Make fbc control wrapper functions
    drm/i915: Wait for the GPU whilst shrinking, if truly desperate.
    drm/i915: Use spatio-temporal dithering on PCH
    [MTD] Remove zero-length files mtdbdi.c and internal.ho
    pata_pcmcia / ide-cs: Fix bad hashes for Transcend and kingston IDs
    libata: Fix several inaccuracies in developer's guide
    slub: Fix bad boundary check in init_kmem_cache_nodes()
    raid6: fix recovery performance regression
    KEYS: call_sbin_request_key() must write lock keyrings before modifying them
    KEYS: Use RCU dereference wrappers in keyring key type code
    KEYS: find_keyring_by_name() can gain access to a freed keyring
    ALSA: hda: Fix 0 dB for Packard Bell models using Conexant CX20549 (Venice)
    ALSA: hda - Add quirk for Dell Inspiron 19T using a Conexant CX20582
    ALSA: take tu->qlock with irqs disabled
    ...

    Dave Airlie
     

18 May, 2010

1 commit


05 May, 2010

1 commit

  • * 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
    drm/radeon/kms/legacy: only enable load detection property on DVI-I
    drm/radeon/kms: fix panel scaling adjusted mode setup
    drivers/gpu/drm/drm_sysfs.c: sysfs files error handling
    drivers/gpu/drm/radeon/radeon_atombios.c: range check issues
    gpu: vga_switcheroo, fix lock imbalance
    drivers/gpu/drm/drm_memory.c: fix check for end of loop
    drivers/gpu/drm/via/via_video.c: fix off by one issue
    drm/radeon/kms/agp The wrong AGP chipset can cause a NULL pointer dereference
    drm/radeon/kms: r300 fix CS checker to allow zbuffer-only fastfill

    Linus Torvalds
     

28 Apr, 2010

1 commit


30 Mar, 2010

1 commit

  • …it 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: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

04 Mar, 2010

1 commit

  • * 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (151 commits)
    vga_switcheroo: disable default y by new rules.
    drm/nouveau: fix *staging* driver build with switcheroo off.
    drm/radeon: fix typo in Makefile
    vga_switcheroo: fix build on platforms with no ACPI
    drm/radeon: Fix printf type warning in 64bit system.
    drm/radeon/kms: bump the KMS version number for square tiling support.
    vga_switcheroo: initial implementation (v15)
    drm/radeon/kms: do not disable audio engine twice
    Revert "drm/radeon/kms: disable HDMI audio for now on rv710/rv730"
    drm/radeon/kms: do not preset audio stuff and start timer when not using audio
    drm/radeon: r100/r200 ums: block ability for userspace app to trash 0 page and beyond
    drm/ttm: fix function prototype to match implementation
    drm/radeon: use ALIGN instead of open coding it
    drm/radeon/kms: initialize set_surface_reg reg for rs600 asic
    drm/i915: Use a dmi quirk to skip a broken SDVO TV output.
    drm/i915: enable/disable LVDS port at DPMS time
    drm/i915: check for multiple write domains in pin_and_relocate
    drm/i915: clean-up i915_gem_flush_gpu_write_domain
    drm/i915: reuse i915_gpu_idle helper
    drm/i915: ensure lru ordering of fence_list
    ...

    Fixed trivial conflicts in drivers/gpu/vga/Kconfig

    Linus Torvalds
     

03 Mar, 2010

1 commit


01 Mar, 2010

3 commits

  • radeon was always including the atpx code unnecessarily, also core
    switcheroo was including acpi headers.

    Signed-off-by: Dave Airlie

    Dave Airlie
     
  • Many new laptops now come with 2 gpus, one to be used for low power
    modes and one for gaming/on-ac applications. These GPUs are typically
    wired to the laptop panel and VGA ports via a multiplexer unit which
    is controlled via ACPI methods.

    4 combinations of systems typically exist - with 2 ACPI methods.
    Intel/ATI - Lenovo W500/T500 - use ATPX ACPI method
    ATI/ATI - some ASUS - use ATPX ACPI Method
    Intel/Nvidia - - use _DSM ACPI method
    Nvidia/Nvidia - - use _DSM ACPI method.

    TODO:
    This patch adds support for the ATPX method and initial bits
    for the _DSM methods that need to written by someone with
    access to the hardware.
    Add a proper non-debugfs interface - need to get some proper
    testing first.

    v2: add power up/down support for both devices
    on W500 puts i915/radeon into D3 and cuts power to radeon.

    v3: redo probing methods, no DMI list, drm devices call to
    register with switcheroo, it tries to find an ATPX method on
    any device and once there is two devices + ATPX it inits the
    switcher.

    v4: ATPX msg handling using buffers - should work on more machines

    v5: rearchitect after more mjg59 discussion - move ATPX handling to
    radeon driver.

    v6: add file headers + initial nouveau bits (to be filled out).

    v7: merge delayed switcher code.

    v8: avoid suspend/resume of gpu that is off

    v9: rearchitect - mjg59 is always right. - move all ATPX code to
    radeon, should allow simpler DSM also proper ATRM handling

    v10: add ATRM support for radeon BIOS, add mutex to lock vgasr_priv

    v11: fix bug in resuming Intel for 2nd time.

    v12: start fixing up nvidia code blindly.

    v13: blindly guess at finishing nvidia code

    v14: remove radeon audio hacks - fix up intel resume more like upstream

    v15: clean up printks + remove unnecessary igd/dis pointers

    mount debugfs

    /sys/kernel/debug/vgaswitcheroo/switch - should exist if ATPX detected
    + 2 cards.

    DIS - immediate change to discrete
    IGD - immediate change to IGD
    DDIS - delayed change to discrete
    DIGD - delayed change to IGD
    ON - turn on not in use
    OFF - turn off not in use

    Tested on W500 (Intel/ATI) and T500 (Intel/ATI)

    Signed-off-by: Dave Airlie

    Dave Airlie
     
  • * 'x86-pci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
    x86: Enable NMI on all cpus on UV
    vgaarb: Add user selectability of the number of GPUS in a system
    vgaarb: Fix VGA arbiter to accept PCI domains other than 0
    x86, uv: Update UV arch to target Legacy VGA I/O correctly.
    pci: Update pci_set_vga_state() to call arch functions

    Linus Torvalds
     

20 Feb, 2010

1 commit

  • Commit 77c1ff3982c6b36961725dd19e872a1c07df7f3b fixed the userspace
    pointer dereference, but introduced another bug pointed out by Eugene Teo
    in RH bug #564264. Instead of comparing the point we were at in the string,
    we instead compared the beginning of the string to "default".

    Signed-off-by: Kyle McMartin
    Reported-by: Eugene Teo
    Signed-off-by: Dave Airlie

    Kyle McMartin
     

11 Feb, 2010

1 commit

  • This patch corrects a userspace pointer dereference in the VGA arbiter
    in 2.6.32.1.

    copy_from_user() is used at line 822 to copy the contents of buf into
    kbuf, but a call to strncmp() on line 964 uses buf rather than kbuf. This
    problem led to a GPF in strncmp() when X was started on my x86_32 systems.
    X triggered the behavior with a write of "target PCI:0000:01:00.0" to
    /dev/vga_arbiter.

    The patch has been tested against 2.6.32.1 and observed to correct the GPF
    observed when starting X or manually writing the string "target
    PCI:0000:01:00.0" to /dev/vga_arbiter.

    Signed-off-by: Andy Getzendanner
    Cc: Jesse Barnes
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Dave Airlie

    Andy Getzendanner
     

06 Feb, 2010

2 commits


10 Sep, 2009

2 commits

  • Fix some warnings reported in linux-next + also cleanup some
    comment errors noticed by Pekka Paalanen.

    Signed-off-by: Dave Airlie
    Signed-off-by: Jesse Barnes

    Dave Airlie
     
  • Background:
    Graphic devices are accessed through ranges in I/O or memory space. While most
    modern devices allow relocation of such ranges, some "Legacy" VGA devices
    implemented on PCI will typically have the same "hard-decoded" addresses as
    they did on ISA. For more details see "PCI Bus Binding to IEEE Std 1275-1994
    Standard for Boot (Initialization Configuration) Firmware Revision 2.1"
    Section 7, Legacy Devices.

    The Resource Access Control (RAC) module inside the X server currently does
    the task of arbitration when more than one legacy device co-exists on the same
    machine. But the problem happens when these devices are trying to be accessed
    by different userspace clients (e.g. two server in parallel). Their address
    assignments conflict. Therefore an arbitration scheme _outside_ of the X
    server is needed to control the sharing of these resources. This document
    introduces the operation of the VGA arbiter implemented for Linux kernel.

    Signed-off-by: Benjamin Herrenschmidt
    Signed-off-by: Tiago Vignatti
    Signed-off-by: Dave Airlie
    Signed-off-by: Jesse Barnes

    Benjamin Herrenschmidt