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    SubjectRe: [PATCH] kernel/printk.c: Concerns about the console handover
    On Fri, Sep 21, 2007 at 02:42:34PM +0200, Gerd Hoffmann wrote:
    > Andrew Morton wrote:
    > > On Thu, 20 Sep 2007 18:28:49 +0100 (BST) "Maciej W. Rozycki" <> wrote:
    > >
    > >> Move the hadover message to after the boot console has been released to
    > >> avoid bad interactions between it and the real console.
    > [ longish problem discussion snipped ]
    > >> considered fully disabled. Below is a change which makes the problem
    > >> disappear for me, but I suppose there was a deliberate reason for placing
    > >> the printk() where it is now and nowhere else.
    > Well, I placed the printk there is for user interface reasons. I think
    > especially in case the early console and the real console go to
    > different physical devices it is useful to have the reason it stops
    > printing messages displayed on the early console. So people don't think
    > the computer hangs although it just prints messages elsewhere ...
    > If that isn't going to work due to two instances not knowing each other
    > (kernel & firmware) should not mess with the same physical device, then
    > I'd just drop the printk. And I see no pretty and easy way around that
    > issue :-(
    > We could do the printk and unregister before we setup the new console.
    > Which has the drawback that we are in trouble in case the setup() call
    > for the new console fails ...
    > We could split the printk into two, one early ("trying to setup new
    > console foo") which goes to the boot console, then (assuming the setup
    > worked ok) unregister silently and print a message about the successful
    > init and boot console unregister on the new console only. Which results
    > in two lines being printed for the handover when both consoles address
    > the same physical device. Not that nice IMHO, but maybe still the best
    > way to handle it.

    I had an issue with the console initialisation on serial ports, which I
    discovered during my PXA work. My reason for asking about the kernel
    versions (which Andrew forwarded to LKML) is to determine whether the
    report is as a result of those changes, or lack of those changes.

    Those -mm versions with git-arm in probably have that change. Ergo
    the importance to answer this question about kernel versions.

    Russell King
    Linux kernel 2.6 ARM Linux -
    maintainer of:
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