44e626f720
Currently, in TX direction, driver implements the TX VLAN offload by checking the VLAN header in skb, and filling it into TX descriptor. Usually it works well, but if enable inserting VLAN header based on port, it may conflict when out_tag field of TX descriptor is already used, and cause RAS error. In RX direction, hardware supports stripping max two VLAN headers. For vlan_tci in skb can only store one VLAN tag, when RX VLAN offload enabled, driver tells hardware to strip one VLAN header from RX packet; when RX VLAN offload disabled, driver tells hardware not to strip VLAN header from RX packet. Now if port based insert VLAN enabled, all RX packets will have the port based VLAN header. This header is useless for stack, driver needs to ask hardware to strip it. Unfortunately, hardware can't drop this VLAN header, and always fill it into RX descriptor, so driver has to identify and drop it. Signed-off-by: Jian Shen <shenjian15@huawei.com> Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.