x86/pci: fix broken ISA DMA
Rene Herman reported: > commit 8779f2fc > > "x86: don't try to allocate from DMA zone at first" > > breaks all of ISA DMA. Or all of ALSA ISA DMA at least. All > ISA soundcards are silent following that commit -- no error > messages, everything appears fine, just silence. That patch is buggy. We had an implicit assumption that dev = NULL for ISA devices that require 24bit DMA. The recent work on x86 dma_alloc_coherent() breaks the ISA DMA buffer allocation, which is represented by "dev = NULL" and requires 24bit DMA implicitly. Bisected-by: NRene Herman <rene.herman@keyaccess.nl> Signed-off-by: NTakashi Iwai <tiwai@suse.de> Tested-by: NRene Herman <rene.herman@keyaccess.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
Showing
想要评论请 注册 或 登录