On Tue, 21 May 2019 10:37:43 +0200, Miartus, Adam (Arion Recruitment; ADITG/ESM) wrote:
On Mon, 20 May 2019 18:51:06 +0200, Miartus, Adam (Arion Recruitment; ADITG/ESM) wrote:
From: Adam Miartus amiartus@de.adit-jv.com
mmap_begin callback is used to copy data from input file to mmaped buffer
guard for corner use of api (multiple mmap_begin calls by user) is introduced to check if next continuous buffer was already overwritten
buffer is overwritten with input file data only in case of stream capture
Signed-off-by: Adam Miartus amiartus@de.adit-jv.com Reviewed-by: Timo Wischer twischer@de.adit-jv.com
Can't we copy the data in snd_pcm_file_mmap_commit() just like the playback case?
thanks,
Takashi
My understanding is that in case of reading data in mmap mode user would call mmap_begin, read the buffer and then call mmap_commit.
In this case overwriting the buffer in mmap_commit with data from Input file would be too late.
Hm, OK. I basically hate to add a new ops, but this might be the only way if we have to implement that.
OTOH, is this mmap support mandatory? IOW, is wrapping with the plug and mmap_emul performance-wise so bad?
thanks,
Takashi