lkml.org 
[lkml]   [2012]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    SubjectRe: [Pkg-xen-devel] ioatdma: Boot process hangs then reboots when using Xen + Linux 3.2
    From
    On Fri, Mar 2, 2012 at 9:57 AM, Bastian Blank <waldi@debian.org> wrote:
    > On Fri, Mar 02, 2012 at 08:44:00AM -0800, Dan Williams wrote:
    >> On Fri, Mar 2, 2012 at 8:21 AM, Bastian Blank <waldi@debian.org> wrote:
    >> > On Thu, Mar 01, 2012 at 10:42:44PM -0800, Dan Williams wrote:
    >> >> WARN_ON may work, but then kernel may be subject random hangs from missed
    >> >> i/o completions.
    >> ...actually descriptors completing too early.
    >
    > The interrupt happens while the module is still loading, so most likely
    > directly after enabling them. There should be no request in flight yet.
    >
    > What puzzles me is the mix of different data types in the ioatdma
    > driver:
    >
    > | u64 completion = *chan->completion;
    > | unsigned long phys_complete = completion & ~0x3f;
    >
    > The state is 64bit long, but is down converted to a 32bit value without
    > anything.
    >
    > phys_complete (a 32 bit value) gets compared to struct
    > dma_async_tx_descriptor.phys, which is defined as dma_addr_t, a _64_ bit
    > value.

    The assumption is that the driver's control structures are not in high
    memory so all address values will only have 32-bits of valid data, but
    maybe xen32 changes that assumption?

    Can you send the log of the driver load with debug enabled?

    diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
    index a4d6cb0..82472de 100644
    --- a/drivers/dma/ioat/dma.c
    +++ b/drivers/dma/ioat/dma.c
    @@ -24,7 +24,7 @@
    * This driver supports an Intel I/OAT DMA engine, which does asynchronous
    * copy operations.
    */
    -
    +#define DEBUG
    #include <linux/init.h>
    #include <linux/module.h>
    #include <linux/slab.h>
    diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
    index 5d65f83..da337e7 100644
    --- a/drivers/dma/ioat/dma_v2.c
    +++ b/drivers/dma/ioat/dma_v2.c
    @@ -24,7 +24,7 @@
    * This driver supports an Intel I/OAT DMA engine (versions >= 2), which
    * does asynchronous data movement and checksumming operations.
    */
    -
    +#define DEBUG
    #include <linux/init.h>
    #include <linux/module.h>
    #include <linux/slab.h>

    \
     
     \ /
      Last update: 2012-03-02 20:35    [W:0.024 / U:0.764 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site