From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dave Mielke <Dave@mielke.cc>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/6] vcs: poll(): cope with a deallocated vt
Date: Wed, 9 Jan 2019 19:13:01 -0500 (EST) [thread overview]
Message-ID: <nycvar.YSQ.7.76.1901091853070.2635@knanqh.ubzr> (raw)
In-Reply-To: <20190109035504.8413-6-nicolas.pitre@linaro.org>
On Tue, 8 Jan 2019, Nicolas Pitre wrote:
> When VT_DISALLOCATE is used on a vt, user space waiting with poll() on
> the corresponding /dev/vcs device is not awakened. This is now fixed by
> returning POLLHUP|POLLERR to user space.
>
> Also, in the normal screen update case, we don't set POLLERR anymore as
> POLLPRI alone is a much more logical response in a non-error situation,
> saving some confusion on the user space side. The only known user app
> making use of poll() on /dev/vcs* is BRLTTY which is known to cope with
> that change already, so the risk of breakage is pretty much nonexistent.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
That patch introduced a small unwanted behavior change that I intend to
fix in a follow-up patch (it will be tagged [PATCH 7/6]). I prefer to go
with a separate patch rather than respinning this one as this gives me
the opportunity to separately document said behavior.
Nicolas
next prev parent reply other threads:[~2019-01-10 0:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 3:54 [PATCH 0/6] assorted console/vt/vcs fixes Nicolas Pitre
2019-01-09 3:54 ` [PATCH 1/6] vt: make vt_console_print() compatible with the unicode screen buffer Nicolas Pitre
2019-01-09 3:55 ` [PATCH 2/6] vt: always call notifier with the console lock held Nicolas Pitre
2019-01-09 3:55 ` [PATCH 3/6] vt: invoke notifier on screen size change Nicolas Pitre
2019-01-09 3:55 ` [PATCH 4/6] vcsa: clamp header values when they don't fit Nicolas Pitre
2019-01-09 3:55 ` [PATCH 5/6] vcs: poll(): cope with a deallocated vt Nicolas Pitre
2019-01-10 0:13 ` Nicolas Pitre [this message]
2019-01-09 3:55 ` [PATCH 6/6] vcs: fasync(): make it consistent with poll() Nicolas Pitre
2019-01-18 12:49 ` [PATCH 0/6] assorted console/vt/vcs fixes Greg Kroah-Hartman
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