This commit adds a new framing mode that frames all MIDI data into
32-byte frames with a timestamp.
The main benefit is that we can get accurate timestamps even if
userspace wakeup and processing is not immediate.
Testing on a Celeron N3150 with this mode has a max jitter of 2.8 ms,
compared to the in-kernel seq implementation which has a max jitter
of 5 ms during idle and much worse when running scheduler stress tests
in parallel.
Signed-off-by: David Henningsson <coding@diwic.se>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210515071533.55332-1-coding@diwic.se
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The struct snd_rawmidi_status will use 'timespec' type variables to record
timestamp, which is not year 2038 safe on 32bits system.
Thus we introduced 'struct snd_rawmidi_status32' and 'struct snd_rawmidi_status64'
to handle 32bit time_t and 64bit time_t in native mode, which replace
timespec with s64 type.
In compat mode, we renamed or introduced new structures to handle 32bit/64bit
time_t in compatible mode. The 'struct snd_rawmidi_status32' and
snd_rawmidi_ioctl_status32() are used to handle 32bit time_t in compat mode.
'struct compat_snd_rawmidi_status64' is used to handle 64bit time_t.
When glibc changes time_t to 64-bit, any recompiled program will issue ioctl
commands that the kernel does not understand without this patch.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some rawmidi compat ioctls lack of the input substream checks
(although they do check only for rfile->output). This many eventually
lead to an Oops as NULL substream is passed to the rawmidi core
functions.
Fix it by adding the proper checks before each function call.
The bug was spotted by syzkaller.
Reported-by: syzbot+f7a0348affc3b67bc617@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Like the previous fixes for ctl and PCM, we need a fix for
incompatible X32 ABI regarding the rawmidi: namely, struct
snd_rawmidi_status has the timespec, and the size and the alignment on
X32 differ from IA32.
This patch fixes the incompatible ioctl for X32.
Cc: <stable@vger.kernel.org> # v3.4+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
David Henningsson