[PATCH v2 2/6] ALSA: hda/tegra: Hardcode GCAP ISS value on T234

Mohan Kumar
2022-02-10T06:51:24Z

The GCAP register on Tegra234 implies no Input Streams(ISS)
supported, but the HW output stream descriptor programming
should start with offset 0x20*4 from base stream descriptor
address. This will be a problem while calculating the offset
for output stream descriptor which will be considering input
stream also. So here output stream starts with offset 0 which
is wrong as HW register for output stream offset starts with 4.
So hardcode the input stream numbers to 4 to avoid the issue
in offset calculation.

Signed-off-by: Mohan Kumar <mkumard@nvidia.com>
---
sound/pci/hda/hda_tegra.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c
index 95df52b0505b..2347d0304f93 100644
--- a/sound/pci/hda/hda_tegra.c
+++ b/sound/pci/hda/hda_tegra.c
@@ -315,6 +315,18 @@ static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev)
* hardcoded value
*/
chip->capture_streams = (gcap >> 8) & 0x0f;
+
+ /* The GCAP register on Tegra234 implies no Input Streams(ISS) support,
+ * but the HW output stream descriptor programming should start with
+ * offset 0x20*4 from base stream descriptor address. This will be a
+ * problem while calculating the offset for output stream descriptor
+ * which will be considering input stream also. So here output stream
+ * starts with offset 0 which is wrong as HW register for output stream
+ * offset starts with 4.
+ */
+ if (of_device_is_compatible(np, "nvidia,tegra234-hda"))
+ chip->capture_streams = 4;
+
chip->playback_streams = (gcap >> 12) & 0x0f;
if (!chip->playback_streams && !chip->capture_streams) {
/* gcap didn't give any info, switching to old method */
--
2.17.1