musb: Babble Interrupt Occurred when I removed the USB cable from USB0

Hi,

Please check this wiki and see if your case is covered: http://processors.wiki.ti.com/index.php/Sitara_Linux_MUSB_Issues If not, please provide more information on how is your USB configured and what device are you connecting to.

- Please provide the usb portion of the schematics if this issue happens on your custom board.

- Please run the attached chkusb.sh script on your board and provide the output.

- Please provide the register dump before remove the cable using the command below.

# grep -i 'power\|devctl' /sys/kernel/debug/musb-hdrc.0.auto/regdump

- Please also provide the register dump after removed the cable using the same command above.

#!/bin/sh
# dump some usb registers
# usbreg.sh <bus-number>
# env: PLATFORM

check_platform() {
	local _hw

	_hw=`grep '^Hardware' /proc/cpuinfo`

	[ "${_hw#*AM33XX}" = "$_hw" ] || { PLATFORM="am335x"; return 0; }
	[ "${_hw#*AM43}" = "$_hw" ] || { PLATFORM="am437x"; return 0; }
	[ "${_hw#*DRA74X}" = "$_hw" ] || { PLATFORM="am57x"; return 0; }
	PLATFORM="unkown"
	return 1
}

[ "$1" = "" ] && {
	echo '    bus #0:'
	$0 0
	echo '    bus #1:'
	$0 1
	exit 0
}

bus=$1

[ "$bus" = "0" ] || [ "$bus" = "1" ] ||
	{ echo "Error: unknown bus number"; exit 1; }

[ "$PLATFORM" != "" ] || check_platform

case $PLATFORM in
	am335x) bus_ent=musb-hdrc.${bus}.auto ;;
	am437x) bus_ent=`printf "%x" $((0x48390000+${bus}*0x40000))`.usb ;;
	am57x) bus_ent=`printf "%x" $((0x48890000+${bus}*0x40000))`.usb ;;
	*)
		echo "Error: unknown platform"
		exit 2 ;;
esac

entry=/sys/kernel/debug/${bus_ent}/regdump

[ -f $entry ] || { echo "$entry not found"; exit 3; }

case $PLATFORM in
	am335x)
		grep 'Power\|DevCtl' $entry ;;
	*)
		grep GCTL $entry
		grep DCTL $entry
		grep 'OCFG\|OCTL\|OSTS' $entry
		;;
esac

Hi Bin,

  Please find attached file for usb reg dump, usbreg script and usb switch schematic.

Thanks & Regards

N Shankarusb.zipusb_reglog.tar.gz

The log does not show when the cable is removed and the babble log. But please try the following patch and let me know if it fixes the issue.

patch: usb: musb: ensure in peripheral mode when checking session
http://marc.info/?l=git-commits-head&m=144331613106445&w=2

Hi Bin,

    After adding patch,then cross compiled and its showing error i.e error: ‘struct usb_otg’ has no member named ‘state’

If I remove state member then no error after check with usb device I am getting same Babble Interrupt Occurred problem please find the below log file and observation

shankar@tata-HP-Elite-7100-Microtower-PC:~/cadb_cust/linux-3.14.26-g2489c02$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=/tools/rootfs_dir/shankar/Rootfs_0810 modules

 CHK     include/config/kernel.release

 CHK     include/generated/uapi/linux/version.h

 CHK     include/generated/utsrelease.h

make[1]: `include/generated/mach-types.h' is up to date.

 CALL    scripts/checksyscalls.sh

 CC [M]  drivers/usb/musb/musb_core.o

drivers/usb/musb/musb_core.c: In function ‘musb_start’:

drivers/usb/musb/musb_core.c:965:64: error: ‘struct usb_otg’ has no member named ‘state’

make[3]: *** [drivers/usb/musb/musb_core.o] Error 1

make[2]: *** [drivers/usb/musb] Error 2

make[1]: *** [drivers/usb] Error 2

make: *** [drivers] Error 2

************************************************ Observations *************************************************************************************************

before inserting pen drive:

root@lifeline:~# ./usb.sh
    bus #0:
Power       : e0
DevCtl      : 88
    bus #1:
/sys/kernel/debug/musb-hdrc.1.auto/regdump not found


umpt@lifeline:~# grep -i 'power\|devctl' /sys/kernel/debug/musb-hdrc.0.auto/regd
Power       : f0
DevCtl      : 89
root@lifeline:~#
root@lifeline:~#

After insert pen drive:

root@lifeline:~# [  257.658287] usb 1-1: new high-speed USB device number 2 using musb-hdrc
[  257.798988] usb 1-1: New USB device found, idVendor=0781, idProduct=5567
[  257.806055] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  257.813601] usb 1-1: Product: Cruzer Blade
[  257.817909] usb 1-1: Manufacturer: SanDisk
[  257.822240] usb 1-1: SerialNumber: 4C530011700411103191
[  257.833848] usb-storage 1-1:1.0: USB Mass Storage device detected
[  257.851408] scsi0 : usb-storage 1-1:1.0
[  258.860334] scsi 0:0:0:0: Direct-Access     SanDisk  Cruzer Blade     1.27 PQ: 0 ANSI: 6
[  258.888446] sd 0:0:0:0: [sda] 30529536 512-byte logical blocks: (15.6 GB/14.5 GiB)
[  258.906510] sd 0:0:0:0: [sda] Write Protect is off
[  258.920118] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[  258.976441]  sda: sda1
[  259.002050] sd 0:0:0:0: [sda] Attached SCSI removable disk
[  259.727414] FAT-fs (sda1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.

root@lifeline:~# ./usb.sh
    bus #0:
Power       : f0
DevCtl      : 5d
    bus #1:
/sys/kernel/debug/musb-hdrc.1.auto/regdump not found
root@lifeline:~#

umpt@lifeline:~# grep -i 'power\|devctl' /sys/kernel/debug/musb-hdrc.0.auto/regdu
Power       : f0
DevCtl      : 5d
root@lifeline:~#

Removing pen drive from board

root@lifeline:~#
root@lifeline:~# [  316.054817] CAUTION: musb: Babble Interrupt Occurred **********
[  316.061154] musb_stage0_irq 788: unhandled DISCONNECT transition (a_wait_bcon)
[  316.069011] usb 1-1: USB disconnect, device number 2
[  316.148270] musb-hdrc musb-hdrc.0.auto: Restarting MUSB to recover from Babble

root@lifeline:~#
root@lifeline:~#
root@lifeline:~#
root@lifeline:~#
umpt@lifeline:~# grep -i 'power\|devctl' /sys/kernel/debug/musb-hdrc.0.auto/regdu
Power       : e0
DevCtl      : 80
root@lifeline:~#
root@lifeline:~# ./usb.sh
    bus #0:
Power       : e0
DevCtl      : 80
    bus #1:
/sys/kernel/debug/musb-hdrc.1.auto/regdump not found
root@lifeline:~#

After bable interrupt occured
root@lifeline:~# ./usb.sh
    bus #0:
Power       : e0
DevCtl      : 80
    bus #1:
/sys/kernel/debug/musb-hdrc.1.auto/regdump not found


Thanks in advance

Thanks&Regards

N Shankar

Shankar,

shankar naragoni said:

    After adding patch,then cross compiled and its showing error i.e error: ‘struct usb_otg’ has no member named ‘state’

I am sorry, this patch was for kernel v4.1, but the SDK8.0 kernel has different 'struct usb_phy'. Please change the patch as follows.

+			musb->xceiv->otg->state != OTG_STATE_A_WAIT_BCON &&

to

+			musb->xceiv->state != OTG_STATE_A_WAIT_BCON &&

The problem is for some reason the controller does not transition to host mode anymore after babble recovery. The transition happens in function otg_timer() in musb_dsps.c.

270         case OTG_STATE_B_IDLE:
271                 if (devctl & MUSB_DEVCTL_BDEVICE) {
272                         musb->xceiv->state = OTG_STATE_B_IDLE;
273                         MUSB_DEV_MODE(musb);
274                 } else {
275                         musb->xceiv->state = OTG_STATE_A_IDLE;
276                         MUSB_HST_MODE(musb);
277                 }
278                 if (!(devctl & MUSB_DEVCTL_SESSION) && !skip_session)
279                         dsps_writeb(mregs, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
280                 mod_timer(&glue->timer, jiffies + wrp->poll_seconds * HZ);
281                 break;

In Line 279 above, bit0 is set to devctl register to trigger the host mode transition. If the patch change I mentioned above does not fix the issue, please debug the piece of code to see if Line 279 got executed after babble happened.