UART DMA unsolicited stop working while transfer huge amount of data

[micham]

Using kernel 3.0.35-I4.0.0 with ttymxc2 activated RTS/CTS and DMA transfer for HCI communication.

During hcd file download approx. 52,7 kB the transfer stops and dmesg shows "We cannot prepare for the RX slave dma!". In this situation sshd cannot accept any new connections. Active ssh connections are not effected. The sshd seems to be a side effect of broken DMA controller.

Is there a fix available in 3.0.35-I4.1.0? If so, is this fix patchable on 4.0.0?

[igorpadykov]

Hi Michael

it is not recommended to use DMA for BT because depending on the BT service could

be a lot of traffic which the DMA could not handle on time.

There was a similar problems on the i.mx53 solved with attached pacthes, one can try them.

Also it is recommended to try latest BSP, since it fixed many SDMA issues.

L3.10.17_1.0.0_IMX6QDLS_BUNDLE : Source Code Download Steps Documentation and Demo Images.

Best regards

igor

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