zoukankan      html  css  js  c++  java
  • sometimes we should use "disable fork" instead of "disable block_name"

    A disable named block statement stops the execution of all blocks with that same name in all threads, which probably causes unexpected behavior.

    Specific to this test, the “disable PM_LINK_WAIT_USB2_L1” statement will stops all active threads of PM_LINK_WAIT_USB2_L1 blocks, even if these PM_LINK_WAIT_USB2_L1 blocks are in different sequences.

    Below I list the process of this issue.

    1. In sequence “fch_usb_multi_port_trans_seqs”, sequence “fch_usb_lpm_trans_seqs” was called twice for each Port.

           //Start transfers for devices

            for(int dn=0;dn<number_of_device;dn++) begin

                automatic int j=dn;

                fork

                    begin

                        for(int k=0;k<2;k++)   begin

                           usb_lpm_trans_seqs[j].otg_xhc_device_transfer= otg_xhc_device_transfer[j];

                           usb_lpm_trans_seqs[j].start(p_sequencer, this);

                        end

                    end

                join_none

            end

    2. In sequence “fch_usb_lpm_trans_seqs”, we need to read register PORTSC_20 to check whether Port is in L1 LPM state.

           //Enter low power

            reg_port_num = otg_xhc_device_transfer.device_cfg.port_number;

            if( pm_controller.pm_link_state == fch_otg_pm_controller::U1_L1 ||

                pm_controller.pm_link_state == fch_otg_pm_controller::U2_L1 ) begin

                fork : PM_LINK_WAIT_USB2_L1

                    begin

                    do begin

                        #5us;

                        expected_pm_link_state = 4'd2;

                        uvm_ext_fd_reg_access(`uvm_ext_fileline,RD,"dwc_usb3_reg","PORTSC_20",reg_data, reg_port_num);

                    end while(reg_data[8:5] != 4'd2);

                    end

                    begin

                        if(otg_xhc_device_transfer.device_cfg.connected_bus_speed == svt_usb_types::LS) begin

                        #3500us;

                        end else if(otg_xhc_device_transfer.device_cfg.connected_bus_speed == svt_usb_types::FS) begin

                        #2500us;

                        end else begin

                        #500us;

                        end

                        `uvm_fatal(get_type_name(), $psprintf("PM: Link, waiting for USB2.0 L1 failed for port %0d", otg_xhc_device_transfer.device_cfg.port_number));

                    end

                join_any

                disable PM_LINK_WAIT_USB2_L1;

                `uvm_info(get_type_name(), $psprintf("PM: Link, Port %0d is L1", otg_xhc_device_transfer.device_cfg.port_number), UVM_LOW);

            end

    3. below waveform snapshot,

    At #T1, usb_lpm_trans_seqs_0 read register PORTSC_20, and the RDATA is 32’h603

    At #T2, usb_lpm_trans_seqs_1 read register PORTSC_20, and the RDATA is 32’h643.

    That is, Port0 is in L1 state, and Port1 is not.

    4. However, The sequence mistakenly checked the Port0 and Port1 were both in L1 state, which was reported in below log.

  • 相关阅读:
    window10使用vagrant+virtualBox搭建centos7
    吾日三思
    搭建EFK过程
    docker端口映射失效解决方法
    centos7防火墙相关命令
    docker学习
    python 读取hive数据
    shell 命令 查看本机ip
    shell 命令 修改hosts文件
    shell 命令 mkdir -p
  • 原文地址:https://www.cnblogs.com/jyaray/p/6077505.html
Copyright © 2011-2022 走看看