USB devio splits large transaction into 16 KiB buffers in scatter-gather
lists. Unfortunately, this mechanism seems unreliable most certainly because
of issue #4809 "DDE Linux struct page object aliasing".
Issue #5036
NCM tries to batch TX packets using timeouts (500us) and does not send packets
before 3 packets are in the submit queue. Timeouts take milliseconds on
dde_linux which leads to delayed ACKs and poor performance for the RX case.
Therefore, we send small packets (<100 Bytes) immediately without batching (it
might be an ACK or last packet of a larger transfer).
issue #4958
The PinePhone Modems' CDC Ethernet Interface does not respond if RX/TX queue size
is greater 12 (experimentally determined), the default would be 60, meaning 60
RX Bulk URBs are sent at once to the device.
issue #4958
Recent devices are configured with 4096 RX pages that lead to an
increased memory usage. For the moment lower the amount to 2048
and treat in potientially lower throughput for more conservative
memory consumption.
Fixes#4801.
Linux kernel static functions usb_string_sub() and usb_get_langid() were
made accessible to implement robust string rerieval.
Fixes#4756Fixes#4757Fixes#4772
Workers are only summoned by the manager or when there are no workers on
a work queue. In case a work in front of a work queue depends on a work
behind it, a deadlock may occur. To solve this Linux spawns a rescue
worker using timers. Timing of Linux based drivers is currently reworked
and not reliable. Therefore, we increase the number of workers that are
spawned from 1 to 3 per work queue in order to resolve possible
deadlocks.
Fixes#4762
Lack of MSI-X support in DDE Linux causes a timeout when the Intel AX211
tries to call back into the driver while loading the PNVM file while
interrupts are still disabled.
With the patch picked up from QubesOS the card works on an X1 Nano G2:
5fcfe0f19e
Issue #4663
