21 May, 2010

6 commits

  • After using state stored in xhci_virt_ep to clean up a stalled endpoint,
    be sure to set the stalled stream ID back to 0.

    Signed-off-by: Sarah Sharp
    Signed-off-by: Greg Kroah-Hartman

    Sarah Sharp
     
  • When a device is disconnected, xhci_free_virt_device() is called. Ramya
    found that if the device had streams enabled, and then the driver freed
    the streams with a call to usb_free_streams(), then about a minute after
    he had called this, his machine crashed with a Bad DMA error. It turns
    out that xhci_free_virt_device() would attempt to free the endpoint's
    stream_info data structure if it wasn't NULL, and the free streams
    function was not setting it to NULL after freeing it.

    Signed-off-by: Sarah Sharp
    Tested-by: Ramya Desai
    Signed-off-by: Greg Kroah-Hartman

    Sarah Sharp
     
  • This patch (as1375) eliminates the usb_host_ss_ep_comp structure used
    for storing a dynamically-allocated copy of the SuperSpeed endpoint
    companion descriptor. The SuperSpeed descriptor is placed directly in
    the usb_host_endpoint structure, alongside the standard endpoint
    descriptor.

    Signed-off-by: Alan Stern
    Signed-off-by: Sarah Sharp
    Signed-off-by: Greg Kroah-Hartman

    Alan Stern
     
  • Much of the xHCI driver code assumes that endpoints only have one ring.
    Now an endpoint can have one ring per enabled stream ID, so correct that
    assumption. Use functions that translate the stream_id field in the URB
    or the DMA address of a TRB into the correct stream ring.

    Correct the polling loop to print out all enabled stream rings. Make the
    URB cancellation routine find the correct stream ring if the URB has
    stream_id set. Make sure the URB enqueueing routine does the same. Also
    correct the code that handles stalled/halted endpoints.

    Check that commands and registers that can take stream IDs handle them
    properly. That includes ringing an endpoint doorbell, resetting a
    stalled/halted endpoint, and setting a transfer ring dequeue pointer
    (since that command can set the dequeue pointer in a stream context or an
    endpoint context).

    Correct the transfer event handler to translate a TRB DMA address into the
    stream ring it was enqueued to. Make the code to allocate and prepare TD
    structures adds the TD to the right td_list for the stream ring. Make
    sure the code to give the first TRB in a TD to the hardware manipulates
    the correct stream ring.

    When an endpoint stalls, store the stream ID of the stream ring that
    stalled in the xhci_virt_ep structure. Use that instead of the stream ID
    in the URB, since an URB may be re-used after it is given back after a
    non-control endpoint stall.

    Signed-off-by: Sarah Sharp
    Signed-off-by: Greg Kroah-Hartman

    Sarah Sharp
     
  • Add support for allocating streams for USB 3.0 bulk endpoints. See
    Documentation/usb/bulk-streams.txt for more information about how and why
    you would use streams.

    When an endpoint has streams enabled, instead of having one ring where all
    transfers are enqueued to the hardware, it has several rings. The ring
    dequeue pointer in the endpoint context is changed to point to a "Stream
    Context Array". This is basically an array of pointers to transfer rings,
    one for each stream ID that the driver wants to use.

    The Stream Context Array size must be a power of two, and host controllers
    can place a limit on the size of the array (4 to 2^16 entries). These
    two facts make calculating the size of the Stream Context Array and the
    number of entries actually used by the driver a bit tricky.

    Besides the Stream Context Array and rings for all the stream IDs, we need
    one more data structure. The xHCI hardware will not tell us which stream
    ID a transfer event was for, but it will give us the slot ID, endpoint
    index, and physical address for the TRB that caused the event. For every
    endpoint on a device, add a radix tree to map physical TRB addresses to
    virtual segments within a stream ring.

    Keep track of whether an endpoint is transitioning to using streams, and
    don't enqueue any URBs while that's taking place. Refuse to transition an
    endpoint to streams if there are already URBs enqueued for that endpoint.

    We need to make sure that freeing streams does not fail, since a driver's
    disconnect() function may attempt to do this, and it cannot fail.
    Pre-allocate the command structure used to issue the Configure Endpoint
    command, and reserve space on the command ring for each stream endpoint.
    This may be a bit overkill, but it is permissible for the driver to
    allocate all streams in one call and free them in multiple calls. (It is
    not advised, however, since it is a waste of resources and time.)

    Even with the memory and ring room pre-allocated, freeing streams can
    still fail because the xHC rejects the configure endpoint command. It is
    valid (by the xHCI 0.96 spec) to return a "Bandwidth Error" or a "Resource
    Error" for a configure endpoint command. We should never see a Bandwidth
    Error, since bulk endpoints do not effect the reserved bandwidth. The
    host controller can still return a Resource Error, but it's improbable
    since the xHC would be going from a more resource-intensive configuration
    (streams) to a less resource-intensive configuration (no streams).

    If the xHC returns a Resource Error, the endpoint will be stuck with
    streams and will be unusable for drivers. It's an unavoidable consequence
    of broken host controller hardware.

    Includes bug fixes from the original patch, contributed by
    John Youn and Andy Green

    Signed-off-by: Sarah Sharp
    Signed-off-by: Greg Kroah-Hartman

    Sarah Sharp
     
  • When the USB core installs a new interface, it unconditionally clears the
    halts on all the endpoints on the new interface. Usually the xHCI host
    needs to know when an endpoint is reset, so it can change its internal
    endpoint state. In this case, it doesn't care, because the endpoints were
    never halted in the first place.

    To avoid issuing a redundant Reset Endpoint command, the xHCI driver looks
    at xhci_virt_ep->stopped_td to determine if the endpoint was actually
    halted. However, the functions that handle the stall never set that
    variable to NULL after it dealt with the stall. So if an endpoint stalled
    and a Reset Endpoint command completed, and then the class driver tried to
    install a new alternate setting, the xHCI driver would access the old
    xhci_virt_ep->stopped_td pointer. A similar problem occurs if the
    endpoint has been stopped to cancel a transfer.

    Signed-off-by: Sarah Sharp
    Cc: stable
    Signed-off-by: Greg Kroah-Hartman

    Sarah Sharp
     

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
     

19 Mar, 2010

2 commits

  • When a signal interrupts a Configure Endpoint command, the cmd_completion used
    in xhci_configure_endpoint() is not re-initialized and the
    wait_for_completion_interruptible_timeout() will return failure. Initialize
    cmd_completion in xhci_configure_endpoint().

    Signed-off-by: Andiry Xu
    Signed-off-by: Sarah Sharp
    Cc: stable
    Signed-off-by: Greg Kroah-Hartman

    Andiry Xu
     
  • Naming consistency with other USB HCDs.

    Signed-off-by: Alex Chiang
    Cc: Sarah Sharp
    Signed-off-by: Greg Kroah-Hartman

    Alex Chiang