BCM Drive Analysis

The DHD driver layer dhd_xxx.c calls the bus Sdio drive layer bcmsdh_sdio_xxx.c and then calls the Fifo,buf,reg of the controller layer and other TX RX operations. In this series of calls, memory, IO,DMA, interrupts and other operations will use some of the OS interface and structure.

Like a generic network driver, the process of the BCM driver, TX data, is to write the Skb_buff data on the hardware header to the TX FIFO or Reg, write to the data Len, and then wait for the hardware TX, which interrupts the CPU after the hardware TX, and then the CPU continues to fill the packet.

The RX data process is when the hardware receives data that interrupts the CPU, initiates an interrupt Isr,isr or skbuff the structure in the Tasklet or work_struct and removes the hardware header, handing it over to the Netif_rx interface, which commits the upper-layer protocol to strip the packet.

BCM Drive Analysis