lkml.org 
[lkml]   [2011]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCHv4 0/4] ARM: Fixing udelay() for SMP and non-SMP systems
    On 03/04/2011 02:10 AM, Linus Walleij wrote:
    > 2010/12/20 Stephen Boyd<sboyd@codeaurora.org>:
    >
    >> These patches fix the udelay() issue pointed out on
    >> arm-lkml[1][2]. A quick recap: some SMP machines can scale
    >> their CPU frequencies independent of one another. loops_per_jiffy
    >> is calibrated globally and used in __const_udelay(). If one CPU
    >> is running faster than what the loops_per_jiffy is calculated
    >> (or scaled) for, udelay() will be incorrect and not wait long
    >> enough (or too long). A similar problem occurs if the cpu
    >> frequency is scaled during a udelay() call.
    >
    > Hwt's happening to this patch set? We have applied it and
    > implemented a timer for the U8500.
    >
    > Tested-by: Linus Walleij<linus.walleij@linaro.org>
    >
    > Mattias WALLIN can probably also provide a Tested-by:
    > from ST-Ericsson if it helps.
    >
    > Generally I think this is good and important stuff that should
    > be merged, will you be submitting it to Russells patch tracker
    > or pull request for 2.6.39?
    >

    Thanks for testing and reporting it Linus. We are certainly interested
    in getting this in. If I'm not mistaken, the last time we sent it out,
    there was a C vs. assembly argument and got side tracked or no one acked
    or responded to it. Will try to send out the patches again within the
    next few weeks.

    Thanks,
    Saravana

    --
    Sent by an employee of the Qualcomm Innovation Center, Inc.
    The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.


    \
     
     \ /
      Last update: 2011-03-06 11:19    [W:4.023 / U:4.436 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site