intel-hda: fix position buffer

Fix position buffer updates to use the correct stream offset.

Without this patch both IN (record) and OUT (playback) streams
will update the IN buffer positions.  The linux kernel notices
and complains:
  hda-intel: Invalid position buffer, using LPIB read method instead.

The bug may also lead to glitches when recording and playing
at the same time:
  https://bugzilla.redhat.com/show_bug.cgi?id=947785

Cc: qemu-stable@nongnu.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/hw/audio/intel-hda.c b/hw/audio/intel-hda.c
index 4327264..6ab8c24 100644 (file)
--- a/hw/audio/intel-hda.c
+++ b/hw/audio/intel-hda.c
@@ -444,6 +444,7 @@ static bool intel_hda_xfer(HDACodecDevice *dev, uint32_t stnr, bool output,
         }
     }
     if (d->dp_lbase & 0x01) {
+        s = st - d->st;
         addr = intel_hda_addr(d->dp_lbase & ~0x01, d->dp_ubase);
         stl_le_pci_dma(&d->pci, addr + 8*s, st->lpib);
     }