Date: Wed, 16 Dec 2015 23:15:41 -0800
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Peter Hurley <peter@hurleysoftware.com>
Cc: Jiri Slaby <jslaby@suse.cz>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/12] Rework tty_reopen()
Message-ID: <20151217071541.GB16626@kroah.com>
References: <1448677557-16420-1-git-send-email-peter@hurleysoftware.com>
 <5671868F.6090508@hurleysoftware.com>
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On Wed, Dec 16, 2015 at 07:43:11AM -0800, Peter Hurley wrote:
> Hi Greg,
> 
> This series has been reported to fix a regression with Redhat's kdump
> systemd service redirecting to /dev/console, when /dev/console is a
> serial port.
> 
> The redirection consistently fails with EIO since
> "tty: Remove tty_wait_until_sent_from_close", which is new to 4.4-rc
> Prior to that patch, redirection would only occasionally fail with EIO. :)
> 
> [  The systemd repeated hangup of /dev/console also seems to be the
> [  trigger for the serial driver crashes on hangup as well, which is
> [  fixed by the 19-patch "Fix driver crashes on hangup" series.
> [  That problem goes back to 3.10, but has only been reported recently,
> [  which leads me to believe recent changes in systemd /dev/console
> [  handling is a contributing factor (which I'm checking right now)
> 
> Here are what I think are the options to resolve the regression:
> 
> #1. Respin this series w/o the tty-next dependencies
> #2. Split this series into the minimum necessary to fix the regression
> #3. Revert from 4.4-rc (in revert order)
>       "tty: Remove wait_event_interruptible_tty()"
>       "tty: r3964: Replace/remove bogus tty lock use"
>       "tty: r3964: Use tty->read_wait waitqueue"
>       "tty: Remove tty_port::close_wait"
>       "usb: gadget: gserial: Privatize close_wait"
>       "tty: Remove ASYNC_CLOSING check in open()/hangup() methods"
>       "tty: Remove tty_wait_until_sent_from_close()"
> 
> Let me know how you'd like me to handle this.

Sounds like a reasonable approach, send the patches on and let's see
what they look like.

thanks,

greg k-h
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