Re: [PATCH v5 0/3] Fix UART DMA freezes for i.MX SOCs

[Jan Lübbe]

On Mon, 2019-09-23 at 17:06 +0200, Philipp Puschmann wrote:
> Thanks for testing.
> With my local setup i still have very few tx timeouts too. But i think they have a different
> cause and especially different consequences. When the problem addressed by this series
> appear you get a whole bunch of tx timeouts (and maybe errors from Bluetooth
> layer) and monitoring received Bluetooth packets with hciconfig shows a
> complete freeze of rx counter. Only resetting the hci_uart driver and the wl1837mon then helps.
> With these patches applied the rx data shold still coming in even if a single or
> multiple tx timeout error happen. I'm not sure where the error comes from and what the
> consequences for the Bluetooth layer are.

For testing, I've used a UART connected to my development host and
configured *mismatching* baud rates. Sending /dev/urandom from the host
to the i.MX6 then triggered the DMA hang (because each character
triggers and error indication, which "uses" a full buffer).

Regards,
Jan
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