Mark Lord [mlord@xxxxxxxxx] [...] > What does this code do: > >static void r8153_set_rx_early_size(struct r8152 *tp) > >{ > > u32 mtu = tp->netdev->mtu; > > u32 ocp_data = (agg_buf_sz - mtu - VLAN_ETH_HLEN - VLAN_HLEN) / 4; > > > > ocp_write_word(tp, MCU_TYPE_USB, USB_RX_EARLY_SIZE, ocp_data); > >} This only works for RTL8153. However, what you use is RTL8152. It is like delay completion. It is used to reduce the loading of CPU by letting a transfer contain more data to reduce the number of transfers. > How is ocp_data used by the hardware? > Shouldn't the calculation also include sizeof(rx_desc) in there somewhere? The algorithm is from our hw engineers, and it should be (agg_buf_sz - packet size) / 8 You could refer to commit a59e6d815226 ("r8152: correct the rx early size").-- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html