linux_dsm_epyc7002/drivers/tty/serial
Douglas Anderson 81eaadcae8 kgdboc: disable the console lock when in kgdb
After commit ddde3c18b7 ("vt: More locking checks") kdb / kgdb has
become useless because my console is filled with spews of:

WARNING: CPU: 0 PID: 0 at .../drivers/tty/vt/vt.c:3846 con_is_visible+0x50/0x74
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc1+ #48
Hardware name: Rockchip (Device Tree)
Backtrace:
[<c020ce9c>] (dump_backtrace) from [<c020d188>] (show_stack+0x20/0x24)
[<c020d168>] (show_stack) from [<c0a8fc14>] (dump_stack+0xb0/0xd0)
[<c0a8fb64>] (dump_stack) from [<c0232c58>] (__warn+0xec/0x11c)
[<c0232b6c>] (__warn) from [<c0232dc4>] (warn_slowpath_null+0x4c/0x58)
[<c0232d78>] (warn_slowpath_null) from [<c06338a0>] (con_is_visible+0x50/0x74)
[<c0633850>] (con_is_visible) from [<c0634078>] (con_scroll+0x108/0x1ac)
[<c0633f70>] (con_scroll) from [<c0634160>] (lf+0x44/0x88)
[<c063411c>] (lf) from [<c06363ec>] (vt_console_print+0x1a4/0x2bc)
[<c0636248>] (vt_console_print) from [<c02f628c>] (vkdb_printf+0x420/0x8a4)
[<c02f5e6c>] (vkdb_printf) from [<c02f6754>] (kdb_printf+0x44/0x60)
[<c02f6714>] (kdb_printf) from [<c02fa6f4>] (kdb_main_loop+0xf4/0x6e0)
[<c02fa600>] (kdb_main_loop) from [<c02fd5f0>] (kdb_stub+0x268/0x398)
[<c02fd388>] (kdb_stub) from [<c02f3ba0>] (kgdb_cpu_enter+0x1f8/0x674)
[<c02f39a8>] (kgdb_cpu_enter) from [<c02f4330>] (kgdb_handle_exception+0x1c4/0x1fc)
[<c02f416c>] (kgdb_handle_exception) from [<c0210fe0>] (kgdb_compiled_brk_fn+0x30/0x3c)
[<c0210fb0>] (kgdb_compiled_brk_fn) from [<c020d7ac>] (do_undefinstr+0x180/0x1a0)
[<c020d62c>] (do_undefinstr) from [<c0201b44>] (__und_svc_finish+0x0/0x3c)
...
[<c02f3224>] (kgdb_breakpoint) from [<c02f3310>] (sysrq_handle_dbg+0x58/0x6c)
[<c02f32b8>] (sysrq_handle_dbg) from [<c062abf0>] (__handle_sysrq+0xac/0x154)

Let's disable this warning when we're in kgdb to avoid the spew.  The
whole system is stopped when we're in kgdb so we can't exactly wait
for someone else to drop the lock.  Presumably the best we can do is
to disable the warning and hope for the best.

Fixes: ddde3c18b7 ("vt: More locking checks")
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20190725183551.169208-1-dianders@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 17:39:39 +02:00
..
8250
cpm_uart
jsm
21285.c
altera_jtaguart.c
altera_uart.c
amba-pl010.c
amba-pl011.c
amba-pl011.h
apbuart.c
apbuart.h
ar933x_uart.c
arc_uart.c
atmel_serial.c
atmel_serial.h
bcm63xx_uart.c
clps711x.c
digicolor-usart.c
dz.c
dz.h
earlycon-arm-semihost.c
earlycon-riscv-sbi.c
earlycon.c
efm32-uart.c
fsl_lpuart.c
icom.c
icom.h
ifx6x60.c
ifx6x60.h
imx.c
ioc3_serial.c
ioc4_serial.c
ip22zilog.c
ip22zilog.h
Kconfig tty: serial: netx: Delete driver 2019-07-25 12:05:28 +02:00
kgdb_nmi.c
kgdboc.c kgdboc: disable the console lock when in kgdb 2019-07-30 17:39:39 +02:00
lantiq.c
lpc32xx_hs.c
Makefile tty: serial: netx: Delete driver 2019-07-25 12:05:28 +02:00
max310x.c
max3100.c
mcf.c
men_z135_uart.c
meson_uart.c
milbeaut_usio.c
mpc52xx_uart.c
mps2-uart.c
msm_serial.c
mux.c
mvebu-uart.c
mxs-auart.c
omap-serial.c
owl-uart.c
pch_uart.c
pic32_uart.c
pic32_uart.h
pmac_zilog.c
pmac_zilog.h
pnx8xxx_uart.c
pxa.c
qcom_geni_serial.c
rda-uart.c
rp2.c
sa1100.c
samsung.c
samsung.h
sb1250-duart.c
sc16is7xx.c
sccnxp.c
serial_core.c
serial_ks8695.c
serial_mctrl_gpio.c
serial_mctrl_gpio.h
serial_txx9.c
serial-tegra.c
sh-sci.c
sh-sci.h
sifive.c
sirfsoc_uart.c
sirfsoc_uart.h
sn_console.c
sprd_serial.c
st-asc.c
stm32-usart.c
stm32-usart.h
suncore.c
sunhv.c
sunsab.c
sunsab.h
sunsu.c
sunzilog.c
sunzilog.h
tegra-tcu.c
timbuart.c
timbuart.h
uartlite.c
ucc_uart.c
vr41xx_siu.c
vt8500_serial.c
xilinx_uartps.c
zs.c
zs.h