From: Arnd Bergmann <arnd@arndb.de>
To: Filip Bozuta <Filip.Bozuta@rt-rk.com>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Laurent Vivier" <laurent@vivier.eu>,
qemu-devel@nongnu.org, "Max Filippov" <jcmvbkbc@gmail.com>,
amarkovic@wavecomp.com, philmd@redhat.com
Subject: Re: [PATCH 08/12] linux-user: Add support for setting alsa timer enhanced read using ioctl
Date: Wed, 15 Jan 2020 20:51:36 +0100 [thread overview]
Message-ID: <CAK8P3a10N3PCkN2mUk7qLTrz6iaO8CYZjGFLWntzwc4L4n_JXw@mail.gmail.com> (raw)
In-Reply-To: <518d717d-9f1e-e00e-f2a9-df8861241d1c@rt-rk.com>
On Wed, Jan 15, 2020 at 8:17 PM Filip Bozuta <Filip.Bozuta@rt-rk.com> wrote:
> On 15.1.20. 17:37, Arnd Bergmann wrote:
> > On Wed, Jan 15, 2020 at 5:32 PM Laurent Vivier <laurent@vivier.eu> wrote:
> >> Le 15/01/2020 à 17:18, Arnd Bergmann a écrit :
> >>> On Wed, Jan 15, 2020 at 4:53 PM Filip Bozuta <Filip.Bozuta@rt-rk.com> wrote:
> >> Do the kernel patches add new ioctl numbers to differentiate 32bit and
> >> 64bit time_t?
> >
> > Yes, though SNDRV_TIMER_IOCTL_TREAD is worse: the ioctl argument
> > is a pure 'int' that decides what format you get when you 'read' from the
> > same file descriptor.
> >
> > For emulating 64-bit on 32-bit kernels, you have to use the new
> > SNDRV_TIMER_IOCTL_TREAD64, and for emulating 32-bit on
> > 64-bit kernels, you probably have to return -ENOTTY to
> > SNDRV_TIMER_IOCTL_TREAD_OLD unless you also want to
> > emulate the read() behavior.
> > When a 32-bit process calls SNDRV_TIMER_IOCTL_TREAD64,
> > you can translate that into the 64-bit
> > SNDRV_TIMER_IOCTL_TREAD_OLD.
>
> Thank you for bringing this up to my attention. Unfortunately i have
> some duties of academic nature in next month so i won't have much time
> fix this bug. I will try to fix this as soon as possible.
One more thing: I just realized it gets worse when emulating cross-endian,
as then even without calling SNDRV_TIMER_IOCTL_TREAD, reading
data from /dev/snd/timer requires byteswapping the two words.
Arnd
next prev parent reply other threads:[~2020-01-15 19:52 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-15 15:53 [PATCH 00/12] linux-user: Add support for real time clock and Filip Bozuta
2020-01-15 15:53 ` [PATCH 01/12] linux-user: Add support for enabling/disabling RTC features using ioctls Filip Bozuta
2020-01-15 15:53 ` [PATCH 02/12] linux-user: Add support for getting/setting RTC time and alarm " Filip Bozuta
2020-01-15 15:53 ` [PATCH 03/12] linux-user: Add support for getting/setting RTC periodic interrupt and epoch " Filip Bozuta
2020-01-15 16:46 ` Laurent Vivier
2020-01-15 15:53 ` [PATCH 04/12] linux-user: Add support for getting/setting RTC wakeup alarm " Filip Bozuta
2020-01-15 15:53 ` [PATCH 05/12] linux-user: Add support for getting/setting RTC PLL correction " Filip Bozuta
2020-01-15 15:53 ` [PATCH 06/12] linux-user: Add support for read/clear RTC voltage low detector " Filip Bozuta
2020-01-15 15:53 ` [PATCH 07/12] linux-user: Add support for getting alsa timer version and id Filip Bozuta
2020-01-15 15:53 ` [PATCH 08/12] linux-user: Add support for setting alsa timer enhanced read using ioctl Filip Bozuta
2020-01-15 16:18 ` Arnd Bergmann
2020-01-15 16:32 ` Laurent Vivier
2020-01-15 16:37 ` Arnd Bergmann
2020-01-15 19:17 ` Filip Bozuta
2020-01-15 19:51 ` Arnd Bergmann [this message]
2020-01-15 21:30 ` Laurent Vivier
2020-01-15 21:52 ` Laurent Vivier
2020-01-16 2:49 ` Aleksandar Markovic
2020-01-16 11:27 ` Aleksandar Markovic
2020-01-16 12:00 ` Arnd Bergmann
2020-01-17 20:50 ` Aleksandar Markovic
2020-01-17 21:45 ` Arnd Bergmann
2020-01-17 21:54 ` Alexandre Belloni
2020-01-15 15:53 ` [PATCH 09/12] linux-user: Add support for getting/setting specified alsa timer parameters using ioctls Filip Bozuta
2020-01-15 15:53 ` [PATCH 10/12] linux-user: Add support for selecting alsa timer using ioctl Filip Bozuta
2020-01-15 15:53 ` [PATCH 11/12] linux-user: Add support for getting/setting selected alsa timer parameters using ioctls Filip Bozuta
2020-01-15 15:53 ` [PATCH 12/12] linux-user: Add support for selected alsa timer instructions " Filip Bozuta
2020-01-15 16:35 ` [PATCH 00/12] linux-user: Add support for real time clock and Laurent Vivier
-- strict thread matches above, loose matches on Subject: below --
2020-01-09 12:59 Filip Bozuta
2020-01-09 12:59 ` [PATCH 08/12] linux-user: Add support for setting alsa timer enhanced read using ioctl Filip Bozuta
2020-01-14 12:44 ` Laurent Vivier
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