linux_dsm_epyc7002/drivers/tty
Matthias Schiffer edd64f3079 tty: serial: imx: disable TXDC IRQ in imx_uart_shutdown() to avoid IRQ storm
The IPG clock is disabled at the end of imx_uart_shutdown(); we really
don't want to run any IRQ handlers after this point.

At least on i.MX8MN, the UART will happily continue to generate interrupts
even with its clocks disabled, but in this state, all register writes are
ignored (which will cause the shadow registers to differ from the actual
register values, resulting in all kinds of weirdness).

In a transfer without DMA, this could lead to the following sequence of
events:

- The UART finishes its transmission while imx_uart_shutdown() is run,
  triggering the TXDC interrupt (we can trigger this fairly reliably by
  writing a single byte to the TTY and closing it right away)
- imx_uart_shutdown() finishes, disabling the UART clocks
- imx_uart_int() -> imx_uart_transmit_buffer() -> imx_uart_stop_tx()

imx_uart_stop_tx() should now clear UCR4_TCEN to disable the TXDC
interrupt, but this register write is ineffective. This results in an
interrupt storm.

To disable all interrupts in the same place, and to avoid setting UCR4
twice, clearing UCR4_OREN is moved below del_timer_sync() as well; this
should be harmless.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20200925082412.12960-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-30 14:31:04 +02:00
..
hvc tty: hvc: fix link error with CONFIG_SERIAL_CORE_CONSOLE=n 2020-09-27 14:17:43 +02:00
ipwireless tty: ipwireless: fix error handling 2020-09-04 18:08:16 +02:00
serdev serdev: Fix detection of UART devices on Apple machines. 2020-03-06 14:10:44 +01:00
serial tty: serial: imx: disable TXDC IRQ in imx_uart_shutdown() to avoid IRQ storm 2020-09-30 14:31:04 +02:00
vt vt_ioctl: make VT_RESIZEX behave like VT_RESIZE 2020-09-27 14:17:43 +02:00
amiserial.c Remove every trace of SERIAL_MAGIC 2019-11-13 19:01:14 +08:00
cyclades.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
ehv_bytechan.c tty: evh_bytechan: Fix out of bounds accesses 2020-03-17 23:40:31 +11:00
goldfish.c headers: separate linux/mod_devicetable.h from linux/platform_device.h 2018-07-07 17:52:26 +02:00
isicom.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile tty: Add NULL TTY driver 2019-04-16 15:21:34 +02:00
mips_ejtag_fdc.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
moxa.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
moxa.h tty: fix spelling mistake 2020-06-27 16:21:20 +02:00
mxser.c tty: mxser: make mxser_change_speed() return void 2020-05-15 14:47:05 +02:00
mxser.h
n_gsm.c Linux 5.9-rc3 2020-08-31 07:19:25 +02:00
n_hdlc.c Linux 5.9-rc3 2020-08-31 07:19:25 +02:00
n_null.c
n_r3964.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
n_tracerouter.c
n_tracesink.c
n_tracesink.h tty: n_tracesink: Use the correct style for SPDX License Identifier 2020-03-18 13:01:31 +01:00
n_tty.c tty: ldiscs, fix kernel-doc 2020-08-18 13:51:18 +02:00
nozomi.c tty: nozomi: Use scnprintf() for avoiding potential buffer overflow 2020-03-18 12:59:29 +01:00
pty.c pty: do tty_flip_buffer_push without port->lock in pty_write 2020-09-04 18:10:30 +02:00
rocket_int.h
rocket.c Merge 5.7-rc3 into tty-next 2020-04-27 09:33:21 +02:00
rocket.h tty: rocket: Remove RCPK_GET_STRUCT ioctl 2019-04-25 11:58:56 +02:00
synclink_gt.c tty: synclink_gt: switch from 'pci_' to 'dma_' API 2020-09-04 18:07:22 +02:00
synclink.c tty: synclink, fix kernel-doc 2020-08-18 13:51:18 +02:00
synclinkmp.c tty: synclink, fix kernel-doc 2020-08-18 13:51:18 +02:00
sysrq.c tty/sysrq: emergency_thaw_all does not depend on CONFIG_BLOCK 2020-06-24 09:16:02 -06:00
tty_audit.c audit: join tty records to their syscall 2019-02-07 21:33:54 -05:00
tty_baudrate.c tty: fix kernel-doc 2020-08-18 13:51:18 +02:00
tty_buffer.c tty: fix kernel-doc 2020-08-18 13:51:18 +02:00
tty_io.c tty: fix kernel-doc 2020-08-18 13:51:18 +02:00
tty_ioctl.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
tty_jobctrl.c tty: fix kernel-doc 2020-08-18 13:51:18 +02:00
tty_ldisc.c tty: fix kernel-doc 2020-08-18 13:51:18 +02:00
tty_ldsem.c locking/lockdep: Remove unused @nested argument from lock_release() 2019-10-09 12:46:10 +02:00
tty_mutex.c
tty_port.c serdev: ttyport: restore client ops on deregistration 2020-02-10 12:26:44 -08:00
ttynull.c tty: Add NULL TTY driver 2019-04-16 15:21:34 +02:00
vcc.c sparc64: vcc: Fix error return code in vcc_probe() 2020-04-28 14:38:54 +02:00