This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM3356: USB Host port recognition issue after wake-up

Part Number: AM3356
Other Parts Discussed in Thread: WL1837MOD, AM3358

Hi Experts,

This thread is related to "https://e2e.ti.com/support/processors/f/791/p/964626/3583530#3583530".

Our customer is developing their system with AM3356/WL1837MOD. Customer configured USB0 port as OTG port and configured USB1 port as USB-Host. For USB OTG port( USB0 ), although AM3356 has been not able to recognize USB Flash after AM3356 did wakeup from standby mode, this issue was resolved with Expert's patch file (above thread). For USB Host port (USB1 port), however, customer encountered similar recognition issue.

Customer attached USB1(Host port) to USB-modem-device, and AM3358 recognized it as serial device ( /dev/ttyACM* ). When AM3356 did wakeup from standby mode, AM3356 was not able to recognize it. I mean, "/dev/ttyACM* " did not appear .Regardless of above patch, this issue seems to occur.

Customer checked USB1_VBUS voltage. I attached it (wakeup_usb2.zip). USB1_VBUS seems to be outputting after wakeup. (I cannot see DP-pullup after VBUS-detection..) Customer is using Linux v4.19 kernel.

Can we have your Expert's advice/comments on this, please?

Best regards,

Miyazaki

  • Hi Miyazaki-san,

    Can you please provide the AM3356 console log after resumed from standby?

  • Hi Bin.

    I attached console-log (dmesg_no_port_appear_Case2_manually.zip).

    The first half is an No-issue-case where the AM335x did not enter standby. The second half is an NG-case, when the AM335x entered standby and waked-up after modem entering sleep.

    Best regards,

    Miyazaki

  • Hi Miyazaki-san,

    Please run the following script on the board after AM335X resumed from standby, and provide its output.

    #!/bin/bash
    #
    # Util to check USB subsystem for Linux kernel 3.12+ on TI Sitara devices
    #
    # Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
    #
    #
    #  Redistribution and use in source and binary forms, with or without
    #  modification, are permitted provided that the following conditions
    #  are met:
    #
    #    Redistributions of source code must retain the above copyright
    #    notice, this list of conditions and the following disclaimer.
    #
    #    Redistributions in binary form must reproduce the above copyright
    #    notice, this list of conditions and the following disclaimer in the
    #    documentation and/or other materials provided with the
    #    distribution.
    #
    #    Neither the name of Texas Instruments Incorporated nor the names of
    #    its contributors may be used to endorse or promote products derived
    #    from this software without specific prior written permission.
    #
    #  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    #  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    #  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    #  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    #  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    #  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    #  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    #  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    #  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    #  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    #  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    
    VERSION=0.3.0
    DTPATH=/proc/device-tree
    DEVPATH=/sys/devices/platform
    KMODPATH="/lib/modules/`uname -r`"
    
    ### ENV
    # $V: debug flag
    # $PLATFORM: force g_plaform if not found in device tree
    
    ### functions ###
    
    # $1 commands to be checked
    check_command() {
        local _lst="$*"
        local _cmd
    
        for _cmd in $_lst; do
            which $_cmd > /dev/null || {
                echo "Error: $_cmd command not found"
                exit 1
            }
        done
    }
    
    # check if the kernel is supported
    # this tool only runs on v4.0+ kernel
    # return 0 - if kernel version >= 4.0
    #        1 - if kernel version < 4.0
    has_supported_kernel() {
    	local _ver
    	local _t
    
        check_command uname
        uname -a
    	_ver=`uname -r`
        _t=${_ver%%.*}
        # 3.x.x or older, unsupported
        [ $_t -ge 4 ] || return 1
        return 0
    }
    
    # define variables for musb entries in sysfs and device tree
    # output variables: USB_DT_PARENT, USB0DT, USB1DT
    #                   USB_DEV_PARENT, USB0DEV, USB1DEV
    query_musb_entries() {
        local _lst
        local _t
        local _intr
    
        check_command find
    
        # find usb entry names in device-tree
        _t=$(find ${DTPATH}/ -maxdepth 2 -name '*47400000*')
        [ -n "$_t" ] && USB_DT_PARENT=$_t || {
            echo "usb parent DT node not found in device-tree"
            exit 1
        }
    
        _lst=$(find ${USB_DT_PARENT}/ -maxdepth 1 -name 'usb@*')
        [ -n "$_lst" ] || {
            echo "usb0 and usb1 DT node not found in device-tree"
            exit 1
        }
    
        # find USB child DT node based on its interrupt number
        for _t in $_lst; do
            [[ -f "${_t}/interrupts" ]] || continue
            _intr=$(hexdump ${_t}/interrupts | head -1 | cut -d' ' -f3)
            case $_intr in
                "1200") USB0DT=$_t;;
                "1300") USB1DT=$_t;;
                *)  echo "unkown usb interrupt number $_intr"
                    exit 1
            esac
        done
    
        # find device names in sysfs
        _t=$(find ${DEVPATH}/ -maxdepth 2 -name '*47400000*')
        [ -n "$_t" ] && USB_DEV_PARENT=$_t || {
            echo "usb device not found in sysfs"
            exit 1
        }
    
        _t=$(find ${USB_DEV_PARENT}/47401400.usb/ -maxdepth 1 -name 'musb-hdrc.*')
        [ -n "$_t" ] && USB0DEV=$_t || echo "usb0 device not found in sysfs"
    
        _t=$(find ${USB_DEV_PARENT}/47401c00.usb/ -maxdepth 1 -name 'musb-hdrc.*')
        [ -n "$_t" ] && USB1DEV=$_t || echo "usb1 device not found in sysfs"
    }
    
    # check if the platform is supported
    # return 0 - if platform is supported
    #        1 - if platform is not supported
    check_platform () {
    	local _hw
    
        check_command grep
        _hw=`cat ${DTPATH}/compatible | tr '\0' ' '`
        DBG_PRINT "DT compatible: $_hw"
    
        if [[ "$_hw" == *"ti,am33xx"* ]]; then
            g_platform="am335x"
        elif [[ "$_hw" == *"ti,am43"* ]]; then
            g_platform="am437x"
        else
            # read from ENV
            g_platform=$PLATFORM
        fi
    
        DBG_PRINT "g_platform: $g_platform"
        case $g_platform in
            "am335x")
                query_musb_entries
                return 0;;
            "am437x")
                USB0DT="$(find $DTPATH -name 'usb@48390000')"
                USB1DT="$(find $DTPATH -name 'usb@483d0000')"
                return 0;;
            *)
                echo "Unsupported \"$g_platform\""
                return 1;;
        esac
    }
    
    # get kernel config options from /proc/config.gz
    # params $@ - the list of config options to query, without 'CONFIG_'
    # return - the config options settings in /proc/config.gz
    get_kernel_configs() {
        local _opts="$@"
        local _lst=""
        local _t
    
        check_command zcat grep
        for _t in $_opts; do
            [ -z "$_lst" ] &&
                _lst="^CONFIG_${_t}\>" ||
                _lst="${_lst}\|^CONFIG_${_t}\>"
        done
        [ -z "$_lst" ] || zcat /proc/config.gz | grep "$_lst"
    }
    
    # check a kernel CONFIG option
    # params $1 - the config option list returned from get_kernel_config()
    #             if "", directly check $2 from /proc/config.gz
    #        $2 - the config option to check
    #        $3 = '-q', quiet output
    # return 0 - undefined
    #        1 - defined as 'm', kernel module
    #        2 - defined as 'y', kernel builtin
    check_kernel_config() {
        local _cfg
        local _t
    
        [ -n "$2" ] || return 0
    
        if [ -z "$1" ]; then
            check_command zcat
            _cfg=`zcat /proc/config.gz | grep "^$2\>"`
        else
            for _t in $1; do
                [[ "$_t" != "${2}="? ]] || { _cfg=$_t; break; }
            done
        fi
    
        case ${_cfg#*=} in
            "y") return 2;;
            "m") return 1;;
              *) [ "$3" = "-q" ] ||
                  echo "Error: $2 is undefined in kernel config"
              return 0;;
        esac
    }
    
    # check a kernel module
    # $1 - module name, relative path from drivers/, without .ko surfix
    # return 0 - found
    #        1 - error
    check_module() {
        local _modname
        local _moddep
    
        [ -n "$1" ] || return 1
    
        _modname="${KMODPATH}/kernel/drivers/${1}.ko"
        _moddep="${KMODPATH}/modules.dep"
    
        DBG_PRINT "${1}.ko checking..."
        [ -f $_modname ] || {
            echo "Error: $_modname not found."
            echo "       Please ensure 'make module_install' is done properly."
            return 1
        }
    
        DBG_PRINT "${1}.ko found"
        [ -f $_moddep ] || $g_printed_once || {
            echo "Error: $_moddep not found."
            echo "       Please ensure 'make module_install' is done properly."
            g_printed_once=true
        }
    
        DBG_PRINT "${1}.ko moddep checked"
        check_command lsmod basename tr
    
        lsmod | grep `basename $1 | tr '-' '_'` > /dev/null || {
            DBG_PRINT ">>>> ${1}.ko not found in lsmod:"
            if grep "${1}.ko:" $_moddep > /dev/null; then
                echo "Error: $_moddep seems to be valid,"
                echo "       but `basename $1`.ko is not loaded."
                echo "       Please provide /proc/config.gz and ${KMODPATH}/*"
                echo "       for further investigation."
            else
                echo "Error: `basename $1`: $_moddep is invalid."
                echo "       Please run command 'depmod' on the target to re-generate it,"
                echo "       then reboot the target. If the issue still exists, please"
                echo "       ensure 'make module_install' is done properly."
            fi
    
            return 1
        }
        DBG_PRINT "${1}.ko done"
        return 0
    }
    
    # check kernel config, and modules (if CONFIG_*=M) for musb
    check_musb_drivers() {
        local _lst=("USB_MUSB_HDRC" "USB_MUSB_DUAL_ROLE" "USB_OTG" "USB_MUSB_DSPS" \
                    "AM335X_PHY_USB" "MUSB_PIO_ONLY" "TI_CPPI41")
        local _opts
    
        _opts=$(get_kernel_configs ${_lst[*]})
    
        check_kernel_config "$_opts" CONFIG_USB_MUSB_HDRC
        [ $? != 1 ] || check_module 'usb/musb/musb_hdrc'
    
        check_kernel_config "$_opts" CONFIG_USB_MUSB_DUAL_ROLE -q
        [ $? != 0 ] || echo "Warning: CONFIG_USB_MUSB_DUAL_ROLE undefined."
    
        check_kernel_config "$_opts" CONFIG_USB_OTG -q
        [ $? == 0 ] || echo "Warning: CONFIG_USB_OTG defined."
    
        check_kernel_config "$_opts" CONFIG_USB_MUSB_DSPS
        [ $? != 1 ] || {
            check_module 'usb/musb/musb_dsps'
        }
    
        check_kernel_config "$_opts" CONFIG_AM335X_PHY_USB
        [ $? != 1 ] || {
            check_module 'usb/phy/phy-am335x'
            check_module 'usb/phy/phy-am335x-control'
        }
    
        check_kernel_config "$_opts" CONFIG_MUSB_PIO_ONLY -q
        [ $? != 0 ] || {
           if check_kernel_config "$_opts" CONFIG_TI_CPPI41 -q; then
               echo "Error: MUSB CPPI DMA mode is enabled, but CPPI moudle is not enabled in DMA Engine."
               echo "       Please enable CONFIG_TI_CPPI41 under DMA Engine Support in kernel config."
           fi
        }
    }
    
    # check kernel config, and modules (if CONFIG_*=M) for dwc3
    check_dwc3_drivers() {
        local _lst=("USB_DWC3" "USB_DWC3_DUAL_ROLE" "USB_OTG" "USB_DWC3_OMAP" \
                    "USB_XHCI_HCD" "OMAP_CONTROL_PHY" "OMAP_USB2")
        local _opts
    
        _opts=$(get_kernel_configs ${_lst[*]})
    
        check_kernel_config "$_opts" CONFIG_USB_DWC3
        [ $? != 1 ] || check_module 'usb/dwc3/dwc3'
    
        check_kernel_config "$_opts" CONFIG_USB_DWC3_DUAL_ROLE -q
        [ $? != 0 ] || echo "Warning: CONFIG_USB_DWC3_DUAL_ROLE undefined."
    
        check_kernel_config "$_opts" CONFIG_USB_OTG -q
        [ $? == 0 ] || echo "Warning: CONFIG_USB_OTG defined."
    
        check_kernel_config "$_opts" CONFIG_USB_DWC3_OMAP
        [ $? != 1 ] || check_module 'usb/dwc3/dwc3-omap'
    
        check_kernel_config "$_opts" CONFIG_USB_XHCI_HCD
        [ $? != 1 ] || {
            check_module 'usb/host/xhci-plat-hcd'
            check_module 'usb/host/xhci-hcd'
        }
    
        check_kernel_config "$_opts" CONFIG_OMAP_CONTROL_PHY
        [ $? != 1 ] || check_module 'phy/phy-omap-control'
    
        check_kernel_config "$_opts" CONFIG_OMAP_USB2
        [ $? != 1 ] || check_module 'phy/phy-omap-usb2'
    }
    
    check_musb_dt() {
        local _dt_dir
        local _ent
        local _sts
        local _t
    
        case $USB_DT_PARENT in
            *"usb@"*)
                _ent=("control@44e10620" "usb-phy@47401300" "usb-phy@47401b00" \
                      "usb@47401000" "usb@47401800" "dma-controller@47402000")
                ;;
            *"target-module@"*)
                _ent=("usb-phy@1300" "usb-phy@1b00" "usb@1400" "usb@1800" \
                      "dma-controller@2000")
                ;;
            *)
                echo "Warning: unknown USB DT ($USB_DT_PARENT)"
                return
        esac
    
        echo "Device Tree USB node status:"
        for _t in '.' ${_ent[*]}; do
            [ -d "${USB_DT_PARENT}/${_t}/" ] || {
                echo -e "\tWarning: USB DT node $_t not found"
                continue
            }
            [ -f "${USB_DT_PARENT}/${_t}/status" ] &&
                _sts=$(tr -d '\0' <${USB_DT_PARENT}/${_t}/status) ||
                _sts="(enabled)"
            echo -e "\t$_t: $_sts"
        done
    }
    
    dump_sysfs_debugfs() {
        local _debugfs
        local _l
        local _f
    
        _debugfs=`sed -ne 's/^debugfs \(.*\) debugfs.*/\1/p' /proc/mounts`
        [ -n "$_debugfs" ] || return
    
        case $g_platform in
            am335x)
                _debugfs=$(find $_debugfs -name 'musb-hdrc.*')
                _debugfs=${_debugfs%/*}
    
                for _f in $USB0DEV $USB1DEV; do
                    _l=$(basename $_f)
                    echo "$_l: mode $(cat ${_f}/mode), $(cat ${_f}/vbus)"
                    grep -i 'power\|devctl\|testmode' ${_debugfs}/${_l}/regdump
                done
                ;;
        esac
    }
    
    check_gadget_kernel_config() {
        local _lst=("USB_ZERO" "USB_AUDIO" "USB_ETH" "USB_G_NCM" "USB_MASS_STORAGE" \
                    "USB_G_SERIAL" "USB_G_PRINTER")
        local _opts
    
        _opts=$(get_kernel_configs ${_lst[*]})
    
        check_kernel_config "$_opts" CONFIG_USB_ZERO -q ||
            echo "Gadget Kernel Config: g_zero is enabled"
        check_kernel_config "$_opts" CONFIG_USB_AUDIO -q ||
            echo "Gadget Kernel Config: g_audio is enabled"
        check_kernel_config "$_opts" CONFIG_USB_ETH -q ||
            echo "Gadget Kernel Config: g_ether is enabled"
        check_kernel_config "$_opts" CONFIG_USB_G_NCM -q ||
            echo "Gadget Kernel Config: g_ncm is enabled"
        check_kernel_config "$_opts" CONFIG_USB_MASS_STORAGE -q ||
            echo "Gadget Kernel Config: g_mass_storage is enabled"
        check_kernel_config "$_opts" CONFIG_USB_G_SERIAL -q ||
            echo "Gadget Kernel Config: g_serial is enabled"
        check_kernel_config "$_opts" CONFIG_USB_G_PRINTER -q ||
            echo "Gadget Kernel Config: g_printer is enabled"
    }
    
    ### debug ###
    
    g_log_file=/tmp/chkusb.log
    
    DBG_ENABLE() { g_dbg_enabled=true; }
    DBG_DISABLE() { g_dbg_enabled=false; }
    DBG_LOG_RESET() { ! $g_dbg_enabled || echo > $g_log_file; }
    DBG_PRINT() { ! $g_dbg_enabled || echo "$(date +%H:%M:%S) [$(basename $0)]: $*"; }
    DBG_LOG() { DBG_PRINT $* >> $g_log_file; }
    DBG_LOG_MARK() { DBG_PRINT "----------------" >> $g_log_file; }
    
    
    ### main ####
    
    g_printed_once=false
    
    echo "chkusb.sh Version $VERSION"
    
    [ "$V" = "1" ] && DBG_ENABLE && DBG_LOG_RESET || DBG_DISABLE
    
    has_supported_kernel ||
        { echo "Unsupported kernel version: `uname -r`"; exit 1; }
    check_platform || exit 2
    DBG_PRINT device: $g_platform
    [ -d ${DTPATH} ] || { echo "Error: ${DTPATH} not found"; exit 3; }
    
    check_command lsusb
    if lsusb > /dev/null 2>&1; then
        echo "USB is initialized"
    else
        echo "USB initialization failed"
    fi
    
    # check kernel configs
    
    if [ -f /proc/config.gz ]; then
        case $g_platform in
            am335x) check_musb_drivers;;
            am437x) check_dwc3_drivers;;
        esac
    else
        echo "Error: /proc/config.gz not found"
    fi
    
    dump_sysfs_debugfs
    
    # check dr_mode & gadget drivers
    
    check_command basename
    for _usb_dir in "${USB0DT}" "${USB1DT}"; do
        [ -n "$_usb_dir" ] || continue
    
        [ -f "$_usb_dir/status" ] &&
            _status=`tr -d '\0' <$_usb_dir/status` ||
            _status='(enabled)'
        _dr_mode=`tr -d '\0'  <$_usb_dir/dr_mode`
        echo `basename $_usb_dir`: $_dr_mode, $_status
    
        [ "$_status" = "disabled" -o "$_dr_mode" = "host" ] || gadget_mode=true
    done
    
    case $g_platform in
        am335x) check_musb_dt;;
        *) ;;
    esac
    
    DBG_PRINT $gadget_mode
    $gadget_mode || exit 0
    
    echo
    
    check_kernel_config "" CONFIG_USB_LIBCOMPOSITE
    case $? in
        0) echo "Error: no any gadget driver enabled"
           exit 6;;
        1) is_gadget_builtin=false;;
        2) echo "The gadget driver is built-in"
           is_gadget_builtin=true;;
    esac
    
    [[ ! -f /proc/config.gz ]] || check_gadget_kernel_config
    
    g_driver=`grep '^DRIVER=' /sys/class/udc/*/uevent 2>/dev/null`
    echo "gadget driver loaded: ${g_driver:-(none)}"
    
    [[ $is_gadget_builtin == false ]] || exit 0
    
    echo
    
    if [ -d "$KMODPATH" ]; then
        echo "The list of USB gadget drivers installed:"
        ls -1Rp ${KMODPATH}/kernel/drivers/usb/gadget/{function,legacy}/
    else
        echo "Error: $KMODPATH not found"
        echo "       Please ensure 'make modules_install' is done properly."
        exit 7
    fi
    
    # vim: ft=sh:ts=4:sw=4:et
    

  • Hi Bn,

    I received log file which the script outputted. I attached it (chkusb.zip).

    It seems, customer is controlling USB1_DRVVBUS. I mean, regarding entering standby mode, customer configures AM3356 to enter standby after customer set USB1_DRVVBUS to "Low". And then, customer sets USB1_DRVVBUS to "High" after resuming from standby.

    it will be appreciated if you will share your quick advice/comments because customer's RTM soon.

    Best regards,

    Miyazaki

  • Hi Miyazaki-san,

    The chkusb.zip output doesn't match to the scope capture (wakeup_usb2.zip) you provided in your first post. the scope capture shows the VBUS is HIGH after resume, but chkusb.zip shows the musb-hdrc.1 register DevCtl = 0x88, which tells the USB1_VBUS is LOW. If VBUS is high, DevCtl register should be 0x19 (before device enumerated) or 0x5D (after high-speed device is enumerated).

    Can you please ask the customer to double check that after resume VBUS should be 5V and chkusb.sh should show musb-hdrc.1/regdump:DevCtl is 0x19 or 0x5D.

    By the way, it seem the scope capture (wakeup_usb2.zip) shows the VBUS is less than 4v when VBUS is HIGH. Please double check it should be > 4.4V.

    Takayuki Miyazaki said:
    customer set USB1_DRVVBUS to "Low". And then, customer sets USB1_DRVVBUS to "High" after resuming from standby

    USB1_DRVVBUS should be automatically controlled by the kernel driver, not touched by anything else. Can you please describe how exactly the customer "controls" this pin to HIGH or LOW?

  • Hi Bin,

    I received customer's feedback because other issue may be fixed..

    Regarding the scope capture which I shared, please ignore it. For current their system, 5V is always supplied to the USB1_VBUS terminal and USB-modem-device even if AM335 entered suspend state (customer had tried to do some modifications). I'm sorry for confusing you...

    I believe this state-transaction is like "Selective Suspend" (keeping VBUS=High/without USB disconnection) which USB2.0 spec defines. I'm not sure if AM335x-SDK is able to support it or not. Can I have your advice/comments on this, please?

    Best regards,

    Miyazaki

  • Hi Miyazaki-san,

    Yes, Selective Suspend is supported in Linux.

    I just tested on AM335x GP EVM with Processor SDK linux v6.03 release, but I don't see any enumeration problem on the USB1 host port after resumed.

    I am not sure I follow your description about "5V is always supplied to USB1_VBUS". Can you please send me the board schematics? I'd like to check the USB design.

  • Hi Bin,

    I received customer’s schematic. I’ll share it offline.USB1_VUS is pullup (5V) and USB1_DRVBUS is connected to VUSB_IN pin of USB-modem device on board.

    There is possibility AM3356 is handling “Selective Suspend”, therefore, after resuming, AM3356 may not try to do enumeration. On the other hand, USB-modem device detect the disconnection (USB1_DRVBUS=OFF), it may expect the enumeration from AM3356 after resuming.

    Can we have your Expert’s advice/comments, please?

    Best regards,

    Miyazaki

  • Hello Bin,

    The customer modified USB1_VBUS to be controlled by USB1_DRVVBUS. However, this issue was not fixed yet. Customer's procedure is as follows.

    1. Power-off USB-modem-device on board

    2. Suspend AM3356 ( systemctl suspend)

    3. Resume AM3356

    4. Power-on USB-modem-device on board

    After that, customer was not able see /dev/ttyACM* (virtual serial port)

     

    Regarding TI GP EVM environment, customer was evaluating this issue as following procedure.

    1. Removed USB Flash

    2. Suspend AM3356 ( systemctl suspend)

    3. Resume AM3356

    4. Attached USB Flash

    customer was not able see /dev/sda1

    customer is considering the device driver has issue. Can I have your advice/comments on this, please ?

     

    Best regards,

    Miyazaki

  • Hi Miyazaki-san,

    Thanks for the details. It helps me finding the root cause. Please revert the kernel patch I provided in the e2e post https://e2e.ti.com/support/processors/f/791/p/964626/3583530#3583530 and apply the patch below (the difference of the two patches is in line 10).

    diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
    index b7d56272f9d1..8eaaadb2d2ed 100644
    --- a/drivers/usb/musb/musb_core.c
    +++ b/drivers/usb/musb/musb_core.c
    @@ -2726,6 +2726,12 @@ static int musb_resume(struct device *dev)
            musb_enable_interrupts(musb);
            musb_platform_enable(musb);
     
    +       /* session might be disabled in suspend */
    +       if (is_host_active(musb)) {
    +               devctl |= MUSB_DEVCTL_SESSION;
    +               musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
    +       }
    +
            spin_lock_irqsave(&musb->lock, flags);
            error = musb_run_resume_work(musb);
            if (error)
    

  • This patch solves the enumeration issue in resume for both USB otg and host ports.

  • Hello Bin,

    Thanks for your strong supports. Customer confirmed this issue was resolved with this patch for both USB OTG and Host ports.

    I really appreciate your help.

    But, since I received one inquiry about OTG recognition, I submit it as following E2E thread.

    https://e2e.ti.com/support/processors/f/791/t/980054

    Best regards,

    Miyazaki