kernel.git/include/uapi/sound/asound.h, branch linux-4.13.y

ALSA: pcm: Add an ioctl to specify the supported protocol version

2017-06-27T11:55:46Z

We have an ioctl to inform the PCM protocol version the running kernel supports, but there is no way to know which protocol version the user-space can understand. This lack of information caused headaches in the past when we tried to extend the ABI. For example, because we couldn't guarantee the validity of the reserved bytes, we had to introduce a new ioctl SNDRV_PCM_IOCTL_STATUS_EXT for assigning a few new fields in the formerly reserved bits. If we could know that it's a new alsa-lib, we could assume the availability of the new fields, thus we could have reused the existing SNDRV_PCM_IOCTL_STATUS. In order to improve the ABI extensibility, this patch adds a new ioctl for user-space to inform its supporting protocol version to the kernel. By reporting the supported protocol from user-space, the kernel can judge which feature should be provided and which not. With the addition of the new ioctl, the PCM protocol version is bumped to 2.0.14, too. User-space checks the kernel protocol version via SNDRV_PCM_INFO_PVERSION, then it sets the supported version back via SNDRV_PCM_INFO_USER_PVERSION. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: pcm: Add the explicit appl_ptr sync support

2017-06-23T13:39:47Z

Currently x86 platforms use the PCM status/control mmaps for transferring the PCM status and appl_ptr between kernel and user-spaces. The mmap is a most efficient way of communication, but it has a drawback per its nature, namely, it can't notify the change explicitly to kernel. The lack of appl_ptr update notification is a problem on a few existing drivers, but it's mostly a small issue and negligible. However, a new type of driver that uses DSP for a deep buffer management requires the exact position of appl_ptr for calculating the buffer prefetch size, and the asynchronous appl_ptr update between kernel and user-spaces becomes a significant problem for it. How can we enforce user-space to report the appl_ptr update? The way is relatively simple. Just by disabling the PCM control mmap, the user-space is supposed to fall back to the mode using SYNC_PTR ioctl, and the kernel gets control over that. This fallback mode is used in all non-x86 platforms as default, and also in the 32bit compatible model on all platforms including x86. It's been implemented already over a decade, so we can say it's fairly safe and stably working. With the help of the knowledge above, this patch introduces a new PCM info flag SNDRV_PCM_INFO_SYNC_APPLPTR for achieving the appl_ptr sync from user-space. When a driver sets this flag at open, the PCM status / control mmap is disabled, which effectively switches to SYNC_PTR mode in user-space side. In this version, both PCM status and control mmaps are disabled although only the latter, control mmap, is the target. It's because the current alsa-lib implementation supposes that both status and control mmaps are always coupled, thus it handles a fatal error when only one of them fails. Of course, the disablement of the status/control mmaps may bring a slight performance overhead. Thus, as of now, this should be used only for the dedicated devices that deserves. Note that the disablement of mmap is a sort of workaround. In the later patch, we'll introduce the way to identify the protocol version alsa-lib supports, and keep mmap working while the sync_ptr is performed together. Reviewed-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: fireface: add hwdep interface

2017-04-05T19:31:49Z

This commit adds hwdep interface so as the other drivers for audio and music units on IEEE 1394 have. This interface is designed for mixer/control applications. By using this interface, an application can get information about firewire node, can lock/unlock kernel streaming and can get notification at starting/stopping kernel streaming. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: firewire-motu: add hwdep interface

2017-03-28T10:34:02Z

This commit adds hwdep interface so as the other sound drivers for units on IEEE 1394 bus have. This interface is designed for mixer/control applications. By using this interface, an application can get information about firewire node, can lock/unlock kernel streaming and can get notification at starting/stopping kernel streaming. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: line6: Add hwdep interface to access the POD control messages

2016-09-19T21:03:47Z

We must do it this way, because e.g. POD X3 won't play any sound unless the host listens on the bulk EP, so we cannot export it only via libusb. The driver currently doesn't use the bulk EP messages in other way, in future it could e.g. sense/modify volume(s). Signed-off-by: Andrej Krutak Signed-off-by: Takashi Iwai

ALSA: timer: remove legacy rtctimer

2016-04-25T08:41:46Z

There are no users of rtctimer left. Remove its code as this is the in-kernel user of the legacy PC RTC driver that will hopefully be removed at some point. Signed-off-by: Alexandre Belloni Signed-off-by: Takashi Iwai

ALSA: uapi: Make alsa asound.h header more portable

2016-03-04T09:50:48Z

This header is used as-is in the alsa-lib userland library, which is portable to other operating systems. For this reason, include linux/types.h only on Linux systems. Add sys/ioctl.h for _IOR/_IOW/etc. (works at least on *BSD and Solaris). Signed-off-by: Thomas Klausner Signed-off-by: Takashi Iwai

ALSA: firewire-tascam: add hwdep interface

2015-10-02T16:17:04Z

This commit adds hwdep interface so as the other IEEE 1394 sound devices has. This interface is designed for mixer/control applications. By using this interface, an application can get information about firewire node, can lock/unlock kernel streaming and can get notification at starting/stopping kernel streaming. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai

ALSA: firewire-digi00x: add hwdep interface

2015-09-30T13:36:56Z

ALSA: asound.h - use SNDRV_CTL_ELEM_ID_NAME_MAXLEN

2015-04-18T07:05:55Z

we have defined SNDRV_CTL_ELEM_ID_NAME_MAXLEN as size of name array so use this define instead of numeric value Signed-off-by: Vinod Koul Signed-off-by: Takashi Iwai