e3cfeefc0e
Adding documentation for all the driver specific sysfs attributes. Cc: Peter Stuge <peter@stuge.se> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
4.6 KiB
What: /sys/class/net//cdc_ncm/min_tx_pkt Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: The driver will pad NCM Transfer Blocks (NTBs) longer than this to tx_max, allowing the device to receive tx_max sized frames with no terminating short packet. NTBs shorter than this limit are transmitted as-is, without any padding, and are terminated with a short USB packet.
Padding to tx_max allows the driver to transmit NTBs
back-to-back without any interleaving short USB
packets. This reduces the number of short packet
interrupts in the device, and represents a tradeoff
between USB bus bandwidth and device DMA optimization.
Set to 0 to pad all frames. Set greater than tx_max to
disable all padding.
What: /sys/class/net//cdc_ncm/rx_max Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: The maximum NTB size for RX. Cannot exceed the maximum value supported by the device. Must allow at least one max sized datagram plus headers.
The actual limits are device dependent. See
dwNtbInMaxSize.
Note: Some devices will silently ignore changes to
this value, resulting in oversized NTBs and
corresponding framing errors.
What: /sys/class/net//cdc_ncm/tx_max Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: The maximum NTB size for TX. Cannot exceed the maximum value supported by the device. Must allow at least one max sized datagram plus headers.
The actual limits are device dependent. See
dwNtbOutMaxSize.
What: /sys/class/net//cdc_ncm/tx_timer_usecs Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: Datagram aggregation timeout in µs. The driver will wait up to 3 times this timeout for more datagrams to aggregate before transmitting an NTB frame.
Valid range: 5 to 4000000
Set to 0 to disable aggregation.
The following read-only attributes all represent fields of the structure defined in section 6.2.1 "GetNtbParameters" of "Universal Serial Bus Communications Class Subclass Specifications for Network Control Model Devices" (CDC NCM), Revision 1.0 (Errata 1), November 24, 2010 from USB Implementers Forum, Inc. The descriptions are quoted from table 6-3 of CDC NCM: "NTB Parameter Structure".
What: /sys/class/net//cdc_ncm/bmNtbFormatsSupported Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: Bit 0: 16-bit NTB supported (set to 1) Bit 1: 32-bit NTB supported Bits 2 – 15: reserved (reset to zero; must be ignored by host)
What: /sys/class/net//cdc_ncm/dwNtbInMaxSize Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: IN NTB Maximum Size in bytes
What: /sys/class/net//cdc_ncm/wNdpInDivisor Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: Divisor used for IN NTB Datagram payload alignment
What: /sys/class/net//cdc_ncm/wNdpInPayloadRemainder Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: Remainder used to align input datagram payload within the NTB: (Payload Offset) mod (wNdpInDivisor) = wNdpInPayloadRemainder
What: /sys/class/net//cdc_ncm/wNdpInAlignment Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: NDP alignment modulus for NTBs on the IN pipe. Shall be a power of 2, and shall be at least 4.
What: /sys/class/net//cdc_ncm/dwNtbOutMaxSize Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: OUT NTB Maximum Size
What: /sys/class/net//cdc_ncm/wNdpOutDivisor Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: OUT NTB Datagram alignment modulus
What: /sys/class/net//cdc_ncm/wNdpOutPayloadRemainder Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: Remainder used to align output datagram payload offsets within the NTB: Padding, shall be transmitted as zero by function, and ignored by host. (Payload Offset) mod (wNdpOutDivisor) = wNdpOutPayloadRemainder
What: /sys/class/net//cdc_ncm/wNdpOutAlignment Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: NDP alignment modulus for use in NTBs on the OUT pipe. Shall be a power of 2, and shall be at least 4.
What: /sys/class/net//cdc_ncm/wNtbOutMaxDatagrams Date: May 2014 KernelVersion: 3.16 Contact: Bjørn Mork bjorn@mork.no Description: Maximum number of datagrams that the host may pack into a single OUT NTB. Zero means that the device imposes no limit.