At Mon, 27 Nov 2006 17:01:52 -0500, David Cullen wrote: > > Dear Folks, > > I am trying to get ALSA version 1.0.13 working on an AMCC PowerPC > PPC405EP Taihu board with a Sound Blaster Live! 24-bit 7.1 PCI card. > I am using a patched 2.6.13 kernel that comes with the board. I > built the kernel with the sound core built in and I used the > cross-compiler tools to build the ALSA driver, library, and utils. > When I run "speaker-test", it crashes in the ALSA library. The > problem is that the call to mmap in > > alsa-lib-1.0.13/src/pcm/pcm_mmap.c line 367 > > which looks like > > ptr = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED, > i->u.mmap.fd, i->u.mmap.offset); > > returns a pointer that appears to be valid (0x3001E000) but causes a > kernel OOPS when accessed. > > Previous calls to mmap in pcm_hw.c on lines 822 and 854 both > succeed, and the pointers returned can be successfully accessed, but > they use the status and control offsets as parameters to mmap. > > I haved traced the problem on the target into the ALSA library using > gdb and into the kernel using kgdb and everything looks like it > works properly. If I disable the semaphore acquisition in do_mmap2, > I can print the contents of the address in kgdb using > > (gdb) print ((char *)vma->vm_start)[0] > > after the call to vm_link in do_mmap_pgoff. However, the board > locks up after the print command. > > Anyone have any experience with this type of problem on PowerPC systems? Possibly a memory coherency problem. The memory allocated via dma_alloc_coherent() isn't simply mmappable. An essential fix would be to add dma_mmap_coherent() to all architectures and use it for ALSA mmap. I made some patches quite ago, but left it rotten for the time being... Takashi ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
