renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-19 02:34:01 +08:00
Code
b3564c2cf4
linux-next/drivers/tty
History
Anton Vorontsov b3564c2cf4 tty/serial/amba-pl011: Implement poll_init callback 
The callback is used to initialize the hardware, nothing else should be
done, i.e. we should not request interrupts (but we can and do unmask
some of them, as they might be useful for NMI entry).

As a side-effect, the patch also fixes a division by zero[1] when booting
with kgdboc options specified (e.g. kgdboc=ttyAMA0,115200n8). The issue
happens because serial core calls set_termios callback, but the driver
doesn't know clock frequency, and thus cannot calculate proper baud rate
values.

[1]
WARNING: at drivers/tty/serial/serial_core.c:400 uart_get_baud_rate+0xe8/0x14c()
Modules linked in:
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c0020ae8>] (warn_slowpath_common+0x4c/0x64)
[<c0020ae8>] (warn_slowpath_common+0x4c/0x64) from [<c0020b1c>] (warn_slowpath_null+0x1c/0x24)
[<c0020b1c>] (warn_slowpath_null+0x1c/0x24) from [<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c)
[<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c) from [<c0187078>] (pl011_set_termios+0x48/0x278)
[<c0187078>] (pl011_set_termios+0x48/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
---[ end trace 7d41c9186f342c40 ]---
Division by zero in kernel.
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10)
[<c014546c>] (Ldiv0+0x8/0x10) from [<c0187098>] (pl011_set_termios+0x68/0x278)
[<c0187098>] (pl011_set_termios+0x68/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
Division by zero in kernel.
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10)
[<c014546c>] (Ldiv0+0x8/0x10) from [<c0183a98>] (uart_update_timeout+0x4c/0x5c)
[<c0183a98>] (uart_update_timeout+0x4c/0x5c) from [<c01870f8>] (pl011_set_termios+0xc8/0x278)
[<c01870f8>] (pl011_set_termios+0xc8/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-26 13:51:31 -07:00
..
hvc tty/serial: remove CONFIG_EXPERIMENTAL dependencies 2012-09-18 16:19:27 +01:00
ipwireless tty: ipwireless: check ppp register worked 2012-09-17 04:45:30 -07:00
serial tty/serial/amba-pl011: Implement poll_init callback 2012-09-26 13:51:31 -07:00
vt tty vt: Fix line garbage in virtual console on command line edition 2012-09-10 16:35:46 -07:00
amiserial.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
bfin_jtag_comm.c TTY: use tty_port_link_device 2012-08-13 16:50:19 -07:00
cyclades.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
ehv_bytechan.c TTY: use tty_port_register_device 2012-08-13 16:50:19 -07:00
isicom.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
Kconfig tty/serial: put (EXPERIMENTAL) marking back on N_GSM and SERIAL_IFX6X60 2012-09-18 17:17:56 +01:00
Makefile tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver 2011-08-23 10:32:56 -07:00
moxa.c TTY: tty_alloc_driver() returns error pointers 2012-08-16 12:07:23 -07:00
moxa.h
mxser.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
mxser.h
n_gsm.c tty: n_gsm: Fix incorrect debug display 2012-09-17 04:45:30 -07:00
n_hdlc.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
n_r3964.c tty: localise the lock 2012-08-10 12:55:47 -07:00
n_tracerouter.c n_tracerouter and n_tracesink ldisc additions. 2011-05-13 16:31:00 -07:00
n_tracesink.c n_tracerouter and n_tracesink ldisc additions. 2011-05-13 16:31:00 -07:00
n_tracesink.h n_tracerouter and n_tracesink ldisc additions. 2011-05-13 16:31:00 -07:00
n_tty.c Remove BUG_ON from n_tty_read() 2012-08-16 11:53:14 -07:00
nozomi.c TTY: use tty_port_register_device 2012-08-13 16:50:19 -07:00
pty.c pty: Fix locking bug on error path 2012-09-21 09:51:09 -07:00
rocket_int.h
rocket.c TTY: use tty_port_register_device 2012-08-13 16:50:19 -07:00
rocket.h
synclink_gt.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
synclink.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
synclinkmp.c serial: add a new helper function 2012-09-05 13:28:35 -07:00
sysrq.c sysrq: use SEND_SIG_FORCED instead of force_sig() 2012-04-05 15:25:50 -07:00
tty_audit.c
tty_buffer.c tty: hold lock across tty buffer finding and buffer filling 2012-04-09 12:12:45 -07:00
tty_io.c tty_register_device_attr updated for tty-next 2012-09-06 14:40:18 -07:00
tty_ioctl.c tty: Fix up PPC fallout from the termios move 2012-07-17 09:10:55 -07:00
tty_ldisc.c tty: localise the lock 2012-08-10 12:55:47 -07:00
tty_mutex.c tty: localise the lock 2012-08-10 12:55:47 -07:00
tty_port.c tty_register_device_attr updated for tty-next 2012-09-06 14:40:18 -07:00