Commit f8b372a1 authored by Ingo Molnar's avatar Ingo Molnar Committed by Linus Torvalds

Revert "8250: Fix tcsetattr to avoid ioctl(TIOCMIWAIT) hang"

This reverts commit 47d3904f.

Crashes any x86 serial console bootup:

  Console: colour VGA+ 80x25
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000158
  IP: [<ffffffff811ebcb4>] serial8250_do_set_termios+0x1d4/0x430
  ...
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c0caf7bc
...@@ -2343,11 +2343,8 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, ...@@ -2343,11 +2343,8 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
/* /*
* CTS flow control flag and modem status interrupts * CTS flow control flag and modem status interrupts
* Only disable MSI if no threads are waiting in
* serial_core::uart_wait_modem_status
*/ */
if (!waitqueue_active(&up->port.state->port.delta_msr_wait)) up->ier &= ~UART_IER_MSI;
up->ier &= ~UART_IER_MSI;
if (!(up->bugs & UART_BUG_NOMSR) && if (!(up->bugs & UART_BUG_NOMSR) &&
UART_ENABLE_MS(&up->port, termios->c_cflag)) UART_ENABLE_MS(&up->port, termios->c_cflag))
up->ier |= UART_IER_MSI; up->ier |= UART_IER_MSI;
......
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