* Andreas Kemnade <andreas@xxxxxxxxxxxx> [180929 22:39]:
> + * needed to disable autoidle, if system power state is too low
> + * hdq transactions will not work correctly, although registers
> + * are accessible.
> + * According to AM/DM3730 TRM p.2879 the hwmod has to way to
> + * keep iclk running during a transfer if autoidle is enabled
Sounds like hdq1w is not wake-up capable and the uart is blocking
deeper SoC idle states. To me it seems that you should rather just
use pm_qos in the hdq1w driver to block SoC idle for the duration
of transfers.
We had a similar problem with audio playback glitches a while
back, see commit 9834ffd1ecc3 ("ASoC: omap-mcbsp: Add PM QoS
support for McBSP to prevent glitches"). See how it does
pm_qos_add_request(), pm_qos_update_request() and
pm_qos_remove_request().
Regards,
Tony
