> > What is required from my part to support memory mapping from the driver > > to the application? Would this be supported through the OSS compatibility > > layer, too? > > hmm... mmap without dma? > how do you transfer the data on buffer to hardware?
The card doesn't support DMA, yet. Data is transferred to/from the buffer by the driver copying 32-bit chunks. Those buffers were allocated by the MMAP, today through the V4Lv2 API (this is an audio+video card). > the copy and silence ops are called when write() is called (more > exactly on alsa it's ioctl) - the thread writing to the device does > actually work like DMA. on mmap mode, there is no such one. so you > need an extra thread (or if it's not too heavy then tasklet might be > available) anyway. Having checked the brief documentation you referred to (http://www.alsa-project.org/alsa-doc/alsa-lib/), I guess using the direct audio buffer to communicate with the device means DMA+MMAP. I would like to do the same thing, but have the driver actually copy data to/from the device. What do you call "mmap mode" above? Is there any other documentation more specific to driver development? Guilhem. __________________________________________________ Do You Yahoo!? Yahoo! Games - play chess, backgammon, pool and more http://games.yahoo.com/ _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
