I am trying to run the ffs-test.c program found in the Linux source tree to work with the USB Gadget framework on the Beaglebone Black. I am getting a kernel panic that has me confused as this program works on other ARM Linux hardware. I am running the 4.1 kernel. Here is the panic:
[ 207.626307] BUG: spinlock bad magic on CPU#0, ffs-test/1379
[ 207.632185] lock: 0xde0273c0, .magic: de0273c0, .owner: <none>/-1, .owner_cpu: -675651324
[ 207.640857] CPU: 0 PID: 1379 Comm: ffs-test Not tainted 4.1.0-rc7-bone70 #5
[ 207.648155] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 207.654570] [<c0012941>] (unwind_backtrace) from [<c00100f3>] (show_stack+0xb/0xc)
[ 207.662518] [<c00100f3>] (show_stack) from [<c0540183>] (dump_stack+0x53/0x68)
[ 207.670105] [<c0540183>] (dump_stack) from [<c0059bb1>] (do_raw_spin_lock+0x101/0x138)
[ 207.678421] [<c0059bb1>] (do_raw_spin_lock) from [<c054424d>] (_raw_spin_lock_irqsave+0xd/0x10)
[ 207.687555] [<c054424d>] (_raw_spin_lock_irqsave) from [<c00feac7>] (kiocb_set_cancel_fn+0x13/0x3c)
[ 207.697067] [<c00feac7>] (kiocb_set_cancel_fn) from [<bf82312f>] (ffs_epfile_read_iter+0x56/0xd4 [usb_f_fs])
[ 207.707391] [<bf82312f>] (ffs_epfile_read_iter [usb_f_fs]) from [<c00d28c1>] (__vfs_read+0x69/0x84)
[ 207.716883] [<c00d28c1>] (__vfs_read) from [<c00d3315>] (vfs_read+0x4d/0xec)
[ 207.724277] [<c00d3315>] (vfs_read) from [<c00d33e1>] (SyS_read+0x2d/0x64)
[ 207.731497] [<c00d33e1>] (SyS_read) from [<c000dbc1>] (ret_fast_syscall+0x1/0x4c)
[ 220.689258] BUG: spinlock lockup suspected on CPU#0, ffs-test/1379
[ 220.695740] lock: 0xde0273c0, .magic: de0273c0, .owner: <none>/-1, .owner_cpu: -675651324
[ 220.704408] CPU: 0 PID: 1379 Comm: ffs-test Not tainted 4.1.0-rc7-bone70 #5
[ 220.711706] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 220.718100] [<c0012941>] (unwind_backtrace) from [<c00100f3>] (show_stack+0xb/0xc)
[ 220.726042] [<c00100f3>] (show_stack) from [<c0540183>] (dump_stack+0x53/0x68)
[ 220.733620] [<c0540183>] (dump_stack) from [<c0059b7f>] (do_raw_spin_lock+0xcf/0x138)
[ 220.741837] [<c0059b7f>] (do_raw_spin_lock) from [<c054424d>] (_raw_spin_lock_irqsave+0xd/0x10)
[ 220.750964] [<c054424d>] (_raw_spin_lock_irqsave) from [<c00feac7>] (kiocb_set_cancel_fn+0x13/0x3c)
[ 220.760461] [<c00feac7>] (kiocb_set_cancel_fn) from [<bf82312f>] (ffs_epfile_read_iter+0x56/0xd4 [usb_f_fs])
[ 220.770777] [<bf82312f>] (ffs_epfile_read_iter [usb_f_fs]) from [<c00d28c1>] (__vfs_read+0x69/0x84)
[ 220.780267] [<c00d28c1>] (__vfs_read) from [<c00d3315>] (vfs_read+0x4d/0xec)
[ 220.787661] [<c00d3315>] (vfs_read) from [<c00d33e1>] (SyS_read+0x2d/0x64)
[ 220.794874] [<c00d33e1>] (SyS_read) from [<c000dbc1>] (ret_fast_syscall+0x1/0x4c)
Here is the startup script:
modprobe libcomposite
modprobe usb_f_fs
mkdir /dev/cfg
mount -t configfs configfs /dev/cfg
mkdir /dev/cfg/usb_gadget/g1
echo "0x2341" > /dev/cfg/usb_gadget/g1/idVendor
echo "0x01AA" > /dev/cfg/usb_gadget/g1/idProduct
mkdir /dev/cfg/usb_gadget/g1/functions/ffs.auto
mkdir /dev/cfg/usb_gadget/g1/configs/c.1
ln -s /dev/cfg/usb_gadget/g1/functions/ffs.auto /dev/cfg/usb_gadget/g1/configs/c.1
echo 0xcd > /dev/cfg/usb_gadget/g1/os_desc/b_vendor_code
echo MSFT100 > /dev/cfg/usb_gadget/g1/os_desc/qw_sign
echo 0 > /dev/cfg/usb_gadget/g1/os_desc/use
echo 0x200 > /dev/cfg/usb_gadget/g1/bcdUSB
mkdir /dev/cfg/usb_gadget/g1/strings/0x409
echo "serialnumber" > /dev/cfg/usb_gadget/g1/strings/0x409/serialnumber
echo "manufacturer" > /dev/cfg/usb_gadget/g1/strings/0x409/manufacturer
echo "Test Device" > /dev/cfg/usb_gadget/g1/strings/0x409/product
mkdir /dev/ffs
mount -t functionfs auto /dev/ffs
And the test program can be found here:
https://github.com/torvalds/linux/blob/master/tools/usb/ffs-test.c
