Tegra serial dma eror


I am seeing error messages of "RxData DMA copy to tty layer failed" in kernel log coming from tegra serial driver.
Apparently, some one else are seeing it too. But no one is has really resolved it.

Although these two tickets are marked as “resolved”, no one has pointed out what the solution is.

hello lunarking1028,

may I know what’s your pin connections and how to repo this failure.
please also have a try with stopping and disabling the nvgetty service.
for example,
systemctl stop nvgetty
systemctl disable nvgetty


After taking look at tegra-serial driver and tty code, I found this is expected behavior and doesn’t hurt anything.
We have a GPS on uart port, and we only write on uart port. However, GPS keeps dumping data on uart port. If we leaves uart port open in our application software, uart/tty port will keep in activated state, and since GPS keeps dumping data on uart, it will keep trigger irq, and tegra-uart driver will keep pushing data to tty buffer, until tty buffer is full.
Since we don’t read on uart from our application software, tty buffer never get consumed, and it will be full at some point. When tty buffer is full, tegra-serial will get error when try to push data to tty buffer, and that’s where that tegra-uart error log came from.

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