On 2021/10/31 1:58, Andrew Lunn wrote:
Rx buf len is buffer length of each rx BD. Use ethtool -g command to get it, and ethtool -G command to set it, examples are as follow: 1. set rx buf len to 4096 $ ethtool -G eth1 rx-buf-len 4096 2. get rx buf len $ ethtool -g eth1 ... RX Buf Len: 4096How does this interact with MTU? If i have an MTU of 1500, and i set the rx-buf-len to 1000, can i expect all frames to the discarded? Should the core return -EINVAL? Or do you think some hardware will simply allocate two buffers and scatter/gather over them? Which implies that drivers which cannot SG must check if the rx-buf-len is less than the MTU and return -EINVAL? Andrew .
Yes, hns3 driver supports scatter/gather for this situation, it's necessary for driver which cannot support SG to check if rx buf len is less than mtu.
