On 1/8/2021 7:29 PM, Peter Geis wrote:
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Currently hda on tegra30 fails to open a stream with an input/output error.
For example: speaker-test -Dhw:0,3 -c 2
speaker-test 1.2.2
Playback device is hw:0,3 Stream parameters are 48000Hz, S16_LE, 2 channels Using 16 octaves of pink noise Rate set to 48000Hz (requested 48000Hz) Buffer size range from 64 to 16384 Period size range from 32 to 8192 Using max buffer size 16384 Periods = 4 was set period_size = 4096 was set buffer_size = 16384 0 - Front Left Write error: -5,Input/output error xrun_recovery failed: -5,Input/output error Transfer failed: Input/output error
The tegra-hda device was introduced in tegra30 but only utilized in tegra124 until recent chips. Tegra210/186 work only due to a hardware change. For this reason it is unknown when this issue first manifested. Discussions with the hardware team show this applies to all current tegra chips. It has been resolved in the tegra234, which does not have hda support at this time.
The explanation from the hardware team is this: Below is the striping formula referenced from HD audio spec. { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
The current issue is seen because Tegra HW has a problem with boundary condition (= 8) for striping. The reason why it is not seen on Tegra210/Tegra186 is because it uses max 2SDO lines. Max SDO lines is read from GCAP register.
For the given stream (channels = 2, bps = 16); ratio = (channels * bps) / NSDO = 32 / NSDO;
On Tegra30, ratio = 32/4 = 8 (FAIL) On Tegra210/186, ratio = 32/2 = 16 (PASS) On Tegra194, ratio = 32/4 = 8 (FAIL) ==> Earlier workaround was applied for it
If Tegra210/186 is forced to use 4SDO, it fails there as well. So the behavior is consistent across all these chips.
Applying the fix in [1] universally resolves this issue on tegra30-hda. Tested on the Ouya game console and the tf201 tablet.
[1] commit 60019d8c650d ("ALSA: hda/tegra: workaround playback failure on Tegra194")
Reviewed-by: Jon Hunter jonathanh@nvidia.com Tested-by: Ion Agorria ion@agorria.com Signed-off-by: Peter Geis pgwipeout@gmail.com
sound/pci/hda/hda_tegra.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Thanks Peter.
Reviewed-by: Sameer Pujar spujar@nvidia.com