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authorStefano Panella <stefano.panella@citrix.com>2013-12-10 14:20:28 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-20 07:34:19 -0800
commit50a715f272de5c786e76607a3cd21489388c5a03 (patch)
tree93e45e611c9bde29ef1b6caf7ff7b706782cbb6f /arch
parenta6079a371fbd4e9cb4489b8a484b559427b97fe1 (diff)
downloadlinux-linaro-stable-50a715f272de5c786e76607a3cd21489388c5a03.tar.gz
ALSA: memalloc.h - fix wrong truncation of dma_addr_t
commit 932e9dec380c67ec15ac3eb073bb55797d8b4801 upstream. When running a 32bit kernel the hda_intel driver is still reporting a 64bit dma_mask if the HW supports it. From sound/pci/hda/hda_intel.c: /* allow 64bit DMA address if supported by H/W */ if ((gcap & ICH6_GCAP_64OK) && !pci_set_dma_mask(pci, DMA_BIT_MASK(64))) pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(64)); else { pci_set_dma_mask(pci, DMA_BIT_MASK(32)); pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(32)); } which means when there is a call to dma_alloc_coherent from snd_malloc_dev_pages a machine address bigger than 32bit can be returned. This can be true in particular if running the 32bit kernel as a pv dom0 under the Xen Hypervisor or PAE on bare metal. The problem is that when calling setup_bdle to program the BLE the dma_addr_t returned from the dma_alloc_coherent is wrongly truncated from snd_sgbuf_get_addr if running a 32bit kernel: static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset) { struct snd_sg_buf *sgbuf = dmab->private_data; dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr; addr &= PAGE_MASK; return addr + offset % PAGE_SIZE; } where PAGE_MASK in a 32bit kernel is zeroing the upper 32bit af addr. Without this patch the HW will fetch the 32bit truncated address, which is not the one obtained from dma_alloc_coherent and will result to a non working audio but can corrupt host memory at a random location. The current patch apply to v3.13-rc3-74-g6c843f5 Signed-off-by: Stefano Panella <stefano.panella@citrix.com> Reviewed-by: Frediano Ziglio <frediano.ziglio@citrix.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions