On 1/30/18 11:42 AM, Takashi Sakamoto wrote:
Hi,
On Jan 30 2018 18:33, Sriram Periyasamy wrote:
From: Ramesh Babu ramesh.babu@intel.com
Add functions to set/get no-rewind flag
Signed-off-by: Ramesh Babu ramesh.babu@intel.com Signed-off-by: Sriram Periyasamy sriramx.periyasamy@intel.com
include/pcm.h | 2 ++ include/sound/asound.h | 1 + src/pcm/pcm.c | 40 ++++++++++++++++++++++++++++++++++++++++ src/pcm/pcm_local.h | 1 + 4 files changed, 44 insertions(+)
For this new flag, I post my comment to your work for kernel land[1]. Please refer to it.
[1] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-January/131336.htm...
I believed we missed your feedback, thanks for providing the pointer.
You wrote "In my opinion, when drivers return appropriate values at implementations of "struct snd_pcm_ops.pointer" and "struct snd_pcm_ops.ack", your aim is satisfied. In short, you can let ALSA PCM core to handle rewinding/forwarding requests from userland for zero number of handled frames in result. So the 'SNDRV_PCM_HW_PARAMS_NO_REWINDS' flag is useless"
You may have missed that the hardware needs to know when the stream is opened if rewinds will be done or not. It's a contract between application and driver, just like the NO_IRQ mode, not a dynamic choice. If we enable the hardware capabilities and the application does a rewind, then it will be a true error with the stream having to be closed. That's not really desirable, is it?
Regards
Takashi Sakamoto _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel