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raspberrypi / linux

Kernel source tree for Raspberry Pi-provided kernel builds. Issues unrelated to the linux kernel should be posted on the community forum at https://forums.raspberrypi.com/
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Raspberry Pi corrupted packets over serial #2506

Closed leragequit closed 6 years ago

leragequit commented 6 years ago

When reading large packets from a Serial -> USB converter I can observe corrupted packages, with invalid or missing data.

This behaviour is only exibited using the raspberry pi linux kernel.

Could test and confirm this with rpi3, cm3, rpi1 model b+ and very late and early iterations ( 4 year ago) of raspbian. The bug was not present in debian aarch64 on rpi3 and cm3, was not present when using the beaglebone.

Can anyone confirm this bug? Read 12k serial from an arduino or s.th. at 921600 baud. bytes should be missing or currupted regardless of hardware used when using the raspberry pi kernel.

Regards, Sascha

edit: the dwc_otc.speed=1 option seems to improve the situation. but considering i have multiple highspeed devices attached this might not be a viable "workaround"

P33M commented 6 years ago

Ah. You have a high baudrate. It's likely that our endpoint throttling is causing FIFO overflows inside your usb-serial adapter.

What happens if you add dwc_otg.nak_holdoff=1 to /boot/cmdline.txt?

P33M commented 6 years ago

No OP response after >2 weeks. Closing unless bug is reported as unfixed.