pcm: pcm_ioplug - fix the avail_update mmap capture copy issue

[GitHub pull_request - opened]

alsa-project/alsa-lib pull request #115 was opened from perexg:

It seems that the commit "pcm: ioplug: Transfer all available data"
introduced new regressions (wrong memory access). The second issue
is that the avail_update in ioplug does not move appl_ptr nor hw_ptr,
so it's possible that the transfers may be repetitive.

This patch moves the transfer calls to mmap_begin callback where it
should be. The pointer wraps are handled by design now.

Fixes: 1714332719 ("pcm: ioplug: Transfer all available data")
BugLink: https://github.com/alsa-project/alsa-lib/pull/103

Request URL   : https://github.com/alsa-project/alsa-lib/pull/115
Patch URL     : https://github.com/alsa-project/alsa-lib/pull/115.patch
Repository URL: https://github.com/alsa-project/alsa-lib