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    SubjectRe: [RESEND PATCH] serial: samsung: fix device name
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    On Mon, Sep 27, 2010 at 3:18 AM, Ben Dooks <ben-linux@fluff.org> wrote:
    > On 24/09/10 17:37, Paulius Zaleckas wrote:
    >> On 09/24/2010 09:57 AM, Darius Augulis wrote:
    >>> Hi,
    >>>
    >>> On Fri, Sep 24, 2010 at 2:40 AM, Ben Dooks<ben-linux@fluff.org>  wrote:
    >>>> On 23/09/10 20:15, Darius Augulis wrote:
    >>>>> Swap device and driver names in serial/samsung.c
    >>>>
    >>>> This is far too short, please see the notes below on trying
    >>>> to make this more informative.
    >>>>
    >>>>> Signed-off-by: Darius Augulis<augulis.darius@gmail.com>
    >>>>> ---
    >>>>>
    >>>>> This patch was submitted about 3 months ago, but still not merged.
    >>>>> There was another similar patch from Joonyoung Shim
    >>>>> <jy0922.shim@samsung.com>  and was discussed here:
    >>>>> http://marc.info/?l=linux-serial&m=127416101222281&w=2.
    >>>>> Joonyoung Shim acked my patch and other people on ARM mailing list
    >>>>> acked it. The maintainer, Ben Dooks, still not responding for
    >>>>> a long time. Another maintainer, Kukjin Kim, refused to merge
    >>>>> it without Ben's review.
    >>>>> I would like to ask somebody pick up this bugfix.
    >>>>
    >>>> I belive last time this was brought up I asked about the affect
    >>>> this has on the userspace. The following issues would be helpful
    >>>> or essential to have noted in the header about the effect of this.
    >>>>
    >>>> - Does it change the /dev name of the device? if so I would thinl
    >>>>   carefully about applying it, as it would be a change in the way
    >>>>   that userspace sees the kernel.
    >>>
    >>> It does - now devices are named /dev/s3c2410_serial, and patch changes
    >>> its name to /dev/ttySAC
    >>>
    >>>>
    >>>> - Does it change the kernel output itself? A note on what diffeences
    >>>>   can be seen in things like dmesg would be helpful.
    >>>
    >>> It does. Serial driver reports device names when probing, so there
    >>> will appear ttySACx instead of
    >>> s3c2410_serialx.
    >>>
    >>>>
    >>>> - Are there any other side effects
    >>>>
    >>>> - Why is this a bug? Maybe the previous points will explain what is
    >>>>   going on, but if not, then a reasonably concise description of
    >>>>   what is going on here.
    >>>
    >>> This is bug, because of several points:
    >>>
    >>> 1. Because it contradicts kernel documentation. Please read
    >>> Documentation/arm/Samsung-S3C24XX/Overview.txt line 196.
    >>> This should be enough to apply this patch.
    >>>
    >>> 2. Because s3c2410_serial isn't correct name for serial device node.
    >>> It's name of Samsung serial driver.
    >>>
    >>> 3. Because now almost all userspace systems workaround it by creating
    >>> symlink
    >>> /dev/ttySACx>  /dev/s3c2410_serialx and only then put some getty on
    >>> created symlink, not on original device.
    >>> Systems which don't create this symlink, fail to boot at all, because
    >>> of wrong console name. Good example is Buildroot.
    >>
    >> I had similar issue with buildroot too, because in /etc/securetty it is
    >> defained as ttySAC0
    >>
    >> 4. For console in kernel boot command line you must enter console=ttySACx.
    >> Why it sould be different in userspace?
    >>
    >> For me it seems taht this bug was not noticed earlier, because most
    >> embedded
    >> systems were using static device nodes and ttySACx was used in these cases.
    >
    > As long as these are explained, then I'm reasonably happy for this to be
    > applied, as long as there are no other complaints.
    >
    > However, this is a big change, and I think it should await the next
    > merge window.

    I also agree that it should be applied to next release.
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