lkml.org 
[lkml]   [2010]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: OMAP3 DSP MMU fault + off mode issue
    From
    Venkii,
    On Wed, Sep 15, 2010 at 9:12 PM, venki kaps <venkiece2005@gmail.com> wrote:
    > Venkii,
    > On Wed, Sep 15, 2010 at 8:02 PM, Kevin Hilman
    > <khilman@deeprootsystems.com> wrote:
    >> venki kaps <venkiece2005@gmail.com> writes:
    >>
    >>> On Tue, Sep 14, 2010 at 8:54 PM, venki kaps <venkiece2005@gmail.com> wrote:
    >>>> On Tue, Sep 14, 2010 at 1:28 AM, venki kaps <venkiece2005@gmail.com> wrote:
    >>>>> Dear all,
    >>>>>
    >>>>> I have been facing an issue with OMAP3 PM with DSP MMU Fault (Kernel 2.6.32).
    >>>>>
    >>>>> The issue is describing as below mentioned way,
    >>>>>        1). The Device is getting DSP MMU Fault when playing MP4 video clip.
    >>>>>
    >>>>> The system is not hitting off mode in the below scenario,
    >>>>>        2). System boot ->play mp4 clip ->DSP MMU Fault -> allow off
    >>>>> mode -----------> Never hits off mode
    >>>>>
    >>>>> But surprisingly the system is hitting off mode in the below scenario,
    >>>>>       3). System boot ->allow off mode ->play mp4 clip ->DSP MMU
    >>>>> Fault -> allow off mode -----------> perfectly works
    >>>>>
    >>>>>
    >>>>>  - Could you please describe the root cause about the above issues 1 & 2?
    >>>>>  - How could solve the above issues?
    >>>>
    >>>> I have found the issue with UART3.
    >>>> In System configuration register (SYSC),-
    >>>>             IDLEMODE  - Smart idle -------> working scenario  ------>
    >>>> system hits off mode.
    >>>>             IDLEMODE  - No idle -------> Non working scenario
    >>>> ------> system never hits off mode.
    >>>>
    >>>> Could you please explain why UART3 is not able to hit smart idle after
    >>>> DSP MMU fault ( System boot ->play mp4 clip ->DSP MMU Fault -> allow
    >>>> off -----------> Never hits off mode).,
    >>>
    >>> My problem is resolved.GPtimer7 was not reset during the MMU FAULT
    >>> occurrence before the first power cycle.
    >>> So this pending interrupt is preventing the system sleep entry.
    >>> Now it works fine after resetting Gptimer7 in pm suspend path.
    >>
    >> Sounds like a patch is needed for DSPBridge who manages that timer.
    >
    > Patchwork DSPBRIDGE: MMU-Fault debugging enhancements,
    > https://patchwork.kernel.org/patch/91577/
    > From the above patch, please see the below comment
    > /*
    >  * Send a GP Timer interrupt to DSP
    >  * The DSP expects a GP timer interrupt after an
    >  * MMU-Fault Request GPTimer
    >  */
    >
    > The above changes allow for DSP task information to be printed
    > by the MPU dspbridge when DSP MMU fault ocurrs.
    >
    > This above changes will be required during development.
    > In my scenario, it is not required so i have just commented.
    >
    > Index: android-2.6.32.9/drivers/dsp/bridge/wmd/ue_deh.c
    > ===================================================================
    > --- android-2.6.32.9.orig/drivers/dsp/bridge/wmd/ue_deh.c
    > 2010-08-24 18:19:19.000000000 +0900
    > +++ android-2.6.32.9/drivers/dsp/bridge/wmd/ue_deh.c    2010-09-16
    > 00:28:52.000000000 +0900
    > @@ -285,7 +285,8 @@
    >                         * The DSP expects a GP timer interrupt after an
    >                         * MMU-Fault Request GPTimer
    >                         */
    > -                       if (timer) {
    > +                       if (0) {
    >                                omap_dm_timer_enable(timer);
    >                                /* Enable overflow interrupt */
    >                                omap_dm_timer_set_int_enable(timer,
    >

    In latest kernels (Eg, linux-2.6.36-rc3),The MMU-Fault debugging
    enhancements code is moved under CONFIG_TIDSPBRIDGE_BACKTRACE.

    >> Kevin
    >>
    >
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2010-09-15 18:07    [W:0.026 / U:3.356 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site