| Message ID | 20190703163355.GA28579@lenoch (mailing list archive) |
|---|---|
| Headers | show |
| Series | usb: gadget: u_serial: Fix and cleanup | expand |
On Wed, Jul 03, 2019 at 06:33:55PM +0200, Ladislav Michl wrote: > Following patchset makes console work (patch 1) for at AT91SAM9G20 board > connected to xhci_hcd and does some cleanup. > Tested with "console=ttyS0,115200n8 console=ttyGS0,115200n8" on kernel > command line and following inittab: > console::respawn:/sbin/getty -L 115200 ttyS0 vt100 > console::respawn:/sbin/getty -L 115200 ttyGS0 vt100 > > There are issues remaining: > > - first usb disconnect works while each next triggers WARN_ON in gs_close: > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 501 at drivers/usb/gadget/function/u_serial.c:706 gs_close+0x3c/0x1e4 > Modules linked in: > CPU: 0 PID: 501 Comm: getty Not tainted 5.2.0-rc7 #44 > Hardware name: Atmel AT91SAM9 > [<c0107514>] (unwind_backtrace) from [<c01051c0>] (show_stack+0x10/0x18) > [<c01051c0>] (show_stack) from [<c05465a8>] (dump_stack+0x18/0x24) > [<c05465a8>] (dump_stack) from [<c010fa80>] (__warn+0xcc/0xe4) > [<c010fa80>] (__warn) from [<c010fad0>] (warn_slowpath_null+0x38/0x48) > [<c010fad0>] (warn_slowpath_null) from [<c03b6648>] (gs_close+0x3c/0x1e4) > [<c03b6648>] (gs_close) from [<c03036b0>] (tty_release+0x1d4/0x460) > [<c03036b0>] (tty_release) from [<c01ce464>] (__fput+0xe4/0x1b0) > [<c01ce464>] (__fput) from [<c0124e1c>] (task_work_run+0x8c/0xa8) > [<c0124e1c>] (task_work_run) from [<c011155c>] (do_exit+0x354/0x814) > [<c011155c>] (do_exit) from [<c0111a9c>] (do_group_exit+0x54/0xb8) > [<c0111a9c>] (do_group_exit) from [<c011a190>] (get_signal+0x18c/0x658) > [<c011a190>] (get_signal) from [<c0104bbc>] (do_work_pending+0xe0/0x44c) > [<c0104bbc>] (do_work_pending) from [<c0101068>] (slow_work_pending+0xc/0x20) > Exception stack(0xc3797fb0 to 0xc3797ff8) > 7fa0: 00000000 beb87d0c 00000001 00000000 > 7fc0: 0009a150 00000000 00099c04 00000003 0009a198 0007e049 00099bd4 0009a1e4 > 7fe0: b6e3f000 beb87cd8 00018210 b6dbcc40 60000010 00000000 > ---[ end trace 70af570fde0de49b ]--- This one is explained in drivers/tty/serial/ip22zilog.c line 751 (see also __tty_hangup) And it also explains why patch 2 in this serie is actually wrong. Will send v2. > - init (both busybox' and systemd) waits for usb host to be plugged in, > otherwise boot is stuck and continues after host is connected. > > Will investigate those two later, however comments and suggestions > to the following patches are appreciated. > > Ladislav Michl (3): > usb: gadget: u_serial: Fix console_req complete event race > usb: gadget: u_serial: Remove console specific alloc/free req > functions > usb: gadget: u_serial: Use bool for req_busy > > drivers/usb/gadget/function/u_serial.c | 88 +++++++++----------------- > 1 file changed, 30 insertions(+), 58 deletions(-) > > -- > 2.20.1 >
On Thu, Jul 04, 2019 at 06:32:56PM +0200, Ladislav Michl wrote: > On Wed, Jul 03, 2019 at 06:33:55PM +0200, Ladislav Michl wrote: > > Following patchset makes console work (patch 1) for at AT91SAM9G20 board > > connected to xhci_hcd and does some cleanup. > > Tested with "console=ttyS0,115200n8 console=ttyGS0,115200n8" on kernel > > command line and following inittab: > > console::respawn:/sbin/getty -L 115200 ttyS0 vt100 > > console::respawn:/sbin/getty -L 115200 ttyGS0 vt100 > > > > There are issues remaining: > > > > - first usb disconnect works while each next triggers WARN_ON in gs_close: > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 501 at drivers/usb/gadget/function/u_serial.c:706 gs_close+0x3c/0x1e4 > > Modules linked in: > > CPU: 0 PID: 501 Comm: getty Not tainted 5.2.0-rc7 #44 > > Hardware name: Atmel AT91SAM9 > > [<c0107514>] (unwind_backtrace) from [<c01051c0>] (show_stack+0x10/0x18) > > [<c01051c0>] (show_stack) from [<c05465a8>] (dump_stack+0x18/0x24) > > [<c05465a8>] (dump_stack) from [<c010fa80>] (__warn+0xcc/0xe4) > > [<c010fa80>] (__warn) from [<c010fad0>] (warn_slowpath_null+0x38/0x48) > > [<c010fad0>] (warn_slowpath_null) from [<c03b6648>] (gs_close+0x3c/0x1e4) > > [<c03b6648>] (gs_close) from [<c03036b0>] (tty_release+0x1d4/0x460) > > [<c03036b0>] (tty_release) from [<c01ce464>] (__fput+0xe4/0x1b0) > > [<c01ce464>] (__fput) from [<c0124e1c>] (task_work_run+0x8c/0xa8) > > [<c0124e1c>] (task_work_run) from [<c011155c>] (do_exit+0x354/0x814) > > [<c011155c>] (do_exit) from [<c0111a9c>] (do_group_exit+0x54/0xb8) > > [<c0111a9c>] (do_group_exit) from [<c011a190>] (get_signal+0x18c/0x658) > > [<c011a190>] (get_signal) from [<c0104bbc>] (do_work_pending+0xe0/0x44c) > > [<c0104bbc>] (do_work_pending) from [<c0101068>] (slow_work_pending+0xc/0x20) > > Exception stack(0xc3797fb0 to 0xc3797ff8) > > 7fa0: 00000000 beb87d0c 00000001 00000000 > > 7fc0: 0009a150 00000000 00099c04 00000003 0009a198 0007e049 00099bd4 0009a1e4 > > 7fe0: b6e3f000 beb87cd8 00018210 b6dbcc40 60000010 00000000 > > ---[ end trace 70af570fde0de49b ]--- > > This one is explained in drivers/tty/serial/ip22zilog.c line 751 (see also > __tty_hangup) And it also explains why patch 2 in this serie is actually wrong. > Will send v2. As an naive approach I tried following: diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 130613751723..4551005a9d23 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -701,6 +704,9 @@ static void gs_close(struct tty_struct *tty, struct file *file) spin_lock_irq(&port->port_lock); + if (test_bit(TTY_HUPPING, &tty->flags)) + goto exit; + if (port->port.count != 1) { if (port->port.count == 0) WARN_ON(1); However this way port->port.count never drops back to zero. Any ideas?
Following patchset makes console work (patch 1) for at AT91SAM9G20 board connected to xhci_hcd and does some cleanup. Tested with "console=ttyS0,115200n8 console=ttyGS0,115200n8" on kernel command line and following inittab: console::respawn:/sbin/getty -L 115200 ttyS0 vt100 console::respawn:/sbin/getty -L 115200 ttyGS0 vt100 There are issues remaining: - first usb disconnect works while each next triggers WARN_ON in gs_close: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 501 at drivers/usb/gadget/function/u_serial.c:706 gs_close+0x3c/0x1e4 Modules linked in: CPU: 0 PID: 501 Comm: getty Not tainted 5.2.0-rc7 #44 Hardware name: Atmel AT91SAM9 [<c0107514>] (unwind_backtrace) from [<c01051c0>] (show_stack+0x10/0x18) [<c01051c0>] (show_stack) from [<c05465a8>] (dump_stack+0x18/0x24) [<c05465a8>] (dump_stack) from [<c010fa80>] (__warn+0xcc/0xe4) [<c010fa80>] (__warn) from [<c010fad0>] (warn_slowpath_null+0x38/0x48) [<c010fad0>] (warn_slowpath_null) from [<c03b6648>] (gs_close+0x3c/0x1e4) [<c03b6648>] (gs_close) from [<c03036b0>] (tty_release+0x1d4/0x460) [<c03036b0>] (tty_release) from [<c01ce464>] (__fput+0xe4/0x1b0) [<c01ce464>] (__fput) from [<c0124e1c>] (task_work_run+0x8c/0xa8) [<c0124e1c>] (task_work_run) from [<c011155c>] (do_exit+0x354/0x814) [<c011155c>] (do_exit) from [<c0111a9c>] (do_group_exit+0x54/0xb8) [<c0111a9c>] (do_group_exit) from [<c011a190>] (get_signal+0x18c/0x658) [<c011a190>] (get_signal) from [<c0104bbc>] (do_work_pending+0xe0/0x44c) [<c0104bbc>] (do_work_pending) from [<c0101068>] (slow_work_pending+0xc/0x20) Exception stack(0xc3797fb0 to 0xc3797ff8) 7fa0: 00000000 beb87d0c 00000001 00000000 7fc0: 0009a150 00000000 00099c04 00000003 0009a198 0007e049 00099bd4 0009a1e4 7fe0: b6e3f000 beb87cd8 00018210 b6dbcc40 60000010 00000000 ---[ end trace 70af570fde0de49b ]--- - init (both busybox' and systemd) waits for usb host to be plugged in, otherwise boot is stuck and continues after host is connected. Will investigate those two later, however comments and suggestions to the following patches are appreciated. Ladislav Michl (3): usb: gadget: u_serial: Fix console_req complete event race usb: gadget: u_serial: Remove console specific alloc/free req functions usb: gadget: u_serial: Use bool for req_busy drivers/usb/gadget/function/u_serial.c | 88 +++++++++----------------- 1 file changed, 30 insertions(+), 58 deletions(-)