Intel Atom processors seem to have a problem at recording when
bdl_pos_adj is set to an odd value. Actually, for the old Atoms, we
set AZX_DRIVER_SCH type, and this assigns 32 as default. Meanwhile
the newer chips, Baytrail and Braswell, are set as AZX_DRIVER_PCH, and
the lower default value, 1, is assigned.
This patch changes the default values for these chipsets to a safer
default, 32, again. Since changing the driver type (AZX_DRIVER_XXX)
leads to the rename of the driver string, it would result in a
possible regression. So, we can't change the type. Instead, in this
patch, manual (ugly) PCI ID checks are added on top.
A drawback by this increase is the slight increase of the latency, but
it's a sub-ms order in normal situations, so mostly negligible.
Reported-and-tested-by: Jochen Henneberg <jh@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/pci/hda/hda_intel.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index a17bf0467edc..56ef6b6fb546 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1490,6 +1490,15 @@ static void azx_probe_work(struct work_struct *work)
static int default_bdl_pos_adj(struct azx *chip)
{
+ /* some exceptions: Atoms seem problematic with value 1 */
+ if (chip->pci->vendor == PCI_VENDOR_ID_INTEL) {
+ switch (chip->pci->device) {
+ case 0x0f04: /* Baytrail */
+ case 0x2284: /* Braswell */
+ return 32;
+ }
+ }
+
switch (chip->driver_type) {
case AZX_DRIVER_ICH:
case AZX_DRIVER_PCH:
--
2.6.4
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