Hi, On the HPPA architecture, devices (including sound ones) are memory-mapped. On particular machines, memory access to devices are not consistent, i.e. data wrote to memory could be cached by the CPU, thus inacessible to the device. To avoid inconsistency in memory writes, there are arch-dep functions that flush write buffers. They are defined in <asm/io.h> as dma_cache_inv(start,size), dma_cache_wback and dma_cache_wback_inv; and should be called after all DMA memory writes.
On architectures that don't have such cache issues (most ia32, ia64, alpha, mips, ppc, ...), they are just NOP. I grepped out the whole alsa source tree and didn't find any occurences of dma_cache_* functions. Who should implement these calls, low level drivers or PCM middle layer ? Thanks for your answer ------------------------------------------------------- This SF.net email is sponsored by: Does your code think in ink? You could win a Tablet PC. Get a free Tablet PC hat just for playing. What are you waiting for? http://ads.sourceforge.net/cgi-bin/redirect.pl?micr5043en _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
