On Fri, 03 Feb 2017 06:28:08 +0100, Satendra Singh Thakur wrote:
From: satendra singh thakur satendra.t@samsung.com
1.Added 2 ioctls in alsa driver's control interface -Added an ioctl to read values of multiple elements at once -Added an ioctl to write values of multiple elements at once -In the absence of above ioctls user needs to call N ioctls to read/write value of N elements which requires N context switches -Proposed ioctls will allow accessing N elements' values in a single context switch -Above mentioned ioctl will be useful for alsa utils such as amixer which reads all controls of given sound card 2. Restructured/Combined two functions snd_ctl_elem_read_user and snd_ctl_elem_write_user into a single function snd_ctl_elem_rw_user -These functions were having most of the code which was similar to each other -Thus, there was redundant/duplicate code which was removed and a single function was formed/defined. -Removed functions snd_ctl_elem_read_user and snd_ctl_elem_write_user having redundant/duplicate code 3. This is version 2 of RFC, here we combine previous 2 patches submitted yesterday (02-Feb) with prefix [RFC] [ALSA][CONTROL] -Fixed doxygen comments related warnings -Fixed stack frame related warning
Signed-off-by: Satendra Singh Thakur satendra.t@samsung.com
Thanks for the patch.
But, could you answer to the question Clemens posted for v1 patch? Namely, do N-times context switching really matter? Does it give the severe performance issue?
If we have a measured number, this thing is worth to consider. OTOH, without the actual measurement but "just because it must be better", it's no good reason for adding a new API/ABI.
thanks,
Takashi