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    SubjectRe: Regression in 4.9-rc1 for PPC32 - bisected to commit 05fd007e4629
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    I have a hack that works. Perhaps it will give a bit more understanding so that 
    a proper patch can be created. My changes were applied on top of 4.9-rc1 with
    the patch from
    https://www.linux-mips.org/archives/linux-mips/2016-10/msg00130.html, and were
    as follows:

    Index: linux/kernel/printk/printk.c
    ===================================================================
    --- linux.orig/kernel/printk/printk.c 2016-10-24 12:29:17.838938604 -0500
    +++ linux/kernel/printk/printk.c 2016-10-24 19:31:20.012593000 -0500
    @@ -2657,7 +2657,9 @@
    * didn't select a console we take the first one
    * that registers here.
    */
    - if (preferred_console < 0 && !of_specified_console) {
    + pr_info("Before: newcon->device %p, newcon->setup %p\n", newcon->device,
    newcon->setup);
    + if ((preferred_console < 0 && !of_specified_console) ||
    + !newcon->setup) {
    if (newcon->index < 0)
    newcon->index = 0;
    if (newcon->setup == NULL ||
    @@ -2670,6 +2672,7 @@
    }
    }

    + pr_info("After: newcon->device %p, newcon->setup %p\n", newcon->device,
    newcon->setup);
    /*
    * See if this console matches one we selected on
    * the command line.
    The changes in commit 05fd007e4629 prevent the body of the 'if
    ((preferred_console < 0 ...' loop from ever being executed; however, the failure
    indicates that we do need to go through this code at least once. I tested
    various quantities, and !newcon->setup was the only one that helped.

    The outputs from the pr_info statements above and the changes in console as
    shown by 'dmesg | egrep "console|newcon" are:
    [ 0.000000] Before: newcon->device (null), newcon->setup (null)
    Part of the body of if executed
    [ 0.000000] After: newcon->device (null), newcon->setup (null)
    [ 0.000000] bootconsole [udbg0] enabled
    [ 0.001581] Before: newcon->device c0326e34, newcon->setup (null)
    We now have newcon->device set, Part of body of if executed
    [ 0.001934] After: newcon->device c0326e34, newcon->setup (null)
    [ 0.002285] console [tty0] enabled
    [ 0.002595] bootconsole [udbg0] disabled
    [ 0.002913] Before: newcon->device c032cc4c, newcon->setup c032cc80
    This time the body of if is not executed and will not be executed anymore.
    [ 0.002925] After: newcon->device c032cc4c, newcon->setup c032cc80
    [ 0.002943] Before: newcon->device c0331ad8, newcon->setup c0331c34
    [ 0.002956] After: newcon->device c0331ad8, newcon->setup c0331c34
    [ 0.003060] Before: newcon->device c0331ad8, newcon->setup c068dbc8
    [ 0.003074] After: newcon->device c0331ad8, newcon->setup c068dbc8
    [ 0.003322] Before: newcon->device c0331ad8, newcon->setup c068ddc4
    [ 0.003335] After: newcon->device c0331ad8, newcon->setup c068ddc4
    [ 1.993661] Before: newcon->device c0331ad8, newcon->setup c068dbc8
    [ 1.993759] After: newcon->device c0331ad8, newcon->setup c068dbc8
    [ 1.994395] Before: newcon->device c0331ad8, newcon->setup c068dbc8
    [ 1.994492] After: newcon->device c0331ad8, newcon->setup c068dbc8
    Larry


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