On Mon, 22 Jul 2019 05:36:50 +0200, Takashi Sakamoto wrote: > > Hi, > > This patchset is for Linux kernel v5.4. > > In current implementation of ALSA IEC 61883-1/6 packet streaming > engine, one callback of isochronous context consists three steps > to process an isochronous packet: > > Callback of isochronous context > - For each of packets > 1.parse context header and decide the amount of PCM frames > 2.process data blocks (in each unit driver) > 3.queue packet > > The result of step 1 affects the rest, thus the above steps can be > changed for below process: > > Callback of isochronous context > 1.parse context header and decide the amount of PCM frames > - For each of packets > 2.process data blocks (in each unit driver) > - For each of packets > 3.queue packet > - For each of packets > > Especially it's convenient to decide the amount of PCM frames > multiplexed into each packet as batch calculation before processing > payloads of these packets. Additionally it allows each unit driver > to process data blocks for these packet by one call. > > This patchset uses list of 'struct pkt_desc' as an intermediate > representation of packet parameters between these three steps. > > > Here, I note my future plan for ALSA firewire stack for your motivation > to review this patchset: > > * v5.4 > * Handle several IT/IR context in one callback of IT context. This > idea will introduce AMDTP domain structure with relationship of IRQ > master/slave between the IT/IR contexts. > * As a result, both of playback/capture PCM substreams run on the > same hardware interrupt. Thus the drivers just support batch PCM > operation and irq-based programming model[1]. > * v5.5 > * Some (p.s. not all) supported devices don't follow packet sequences > transferred by the drivers. They require clock recovery in driver > side to reduce playback noise. Enhance the AMDTP domain structure > to have clock recovery target and fill list of 'struct pkt_desc' > according to the result of clock recovery. > > My work for libhinoko[2] allows me to sniff actual packet transmission > between devices and drivers in Windows/Mac OS for long period (e.g. 1 > hour). Then I can classify some cases and some devices for the > requirement of clock recovery. > > (I note that no specification describes this mechanism as long as I know. > In the specification, clock recovery is one-way from transmitter to > receivers, thus recovered clock is not necessarily used for transmission > from the receiver to the transmitter.) > > [1] https://git.alsa-project.org/?p=alsa-utils.git;a=blob;f=axfer/axfer-transfer.1;hb=HEAD#l675 > [2] https://github.com/takaswie/libhinoko > > Takashi Sakamoto (20): > ALSA: firewire-lib: obsolete ctx_data.tx.first_dbc with > CIP_UNALIGHED_DBC flag > ALSA: firewire-lib: pass data block count as an argument to > tracepoints event > ALSA: firewire-lib: pass data block counter to data block processing > layer > ALSA: firewire-lib: operate data block counter in top level of > processing for IT context > ALSA: firewire-lib: operate data block counter in top level of > processing for IR context > ALSA: firewire-lib: add syt_override member for some protocols > ALSA: firewire-lib: pass no syt information to data block processing > layer > ALSA: firewire-lib: add list of packet descriptor > ALSA: firewire-lib: use packet descriptor for IT context > ALSA: firewire-lib: use packet descriptor for IR context > ALSA: firewire-lib: code refactoring to process PCM substream > ALSA: firewire-lib: code refactoring to process context payloads > ALSA: firewire-lib: pass packet descriptor to data block processing > layer > ALSA: firewire-lib: code refactoring for AM824 data block processing > layer > ALSA: firewire-digi00x: code refactoring for DOT data block processing > layer > ALSA: firewire-tascam: code refactoring for TASCAM data block > processing layer > ALSA: firewire-motu: code refactoring for MOTU data block processing > layer > ALSA: fireface: code refactoring for FF data block processing layer > ALSA: firewire-lib: process payload of isoc context according to > packet descriptors > ALSA: firewire-motu: more code refactoring for MOTU data block > processing layer Applied all 20 patches now. Thanks. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
