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93a770b7e1
struct uart_port contains a cached copy of the Modem Control signals. It is used to skip register writes in uart_update_mctrl() if the new signal state equals the old signal state. It also avoids a register read to obtain the current state of output signals. When a uart_port is registered, uart_configure_port() changes signal state but neglects to keep the cached copy in sync. That may cause a subsequent register write to be incorrectly skipped. Fix it before it trips somebody up. This behavior has been present ever since the serial core was introduced in 2002: https://git.kernel.org/history/history/c/33c0d1b0c3eb So far it was never an issue because the cached copy is initialized to 0 by kzalloc() and when uart_configure_port() is executed, at most DTR has been set by uart_set_options() or sunsu_console_setup(). Therefore, a stable designation seems unnecessary. Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/bceeaba030b028ed810272d55d5fc6f3656ddddb.1641129752.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| .. | ||
| hvc | ||
| ipwireless | ||
| serdev | ||
| serial | ||
| vt | ||
| amiserial.c | ||
| ehv_bytechan.c | ||
| goldfish.c | ||
| Kconfig | ||
| Makefile | ||
| mips_ejtag_fdc.c | ||
| moxa.c | ||
| mxser.c | ||
| n_gsm.c | ||
| n_hdlc.c | ||
| n_null.c | ||
| n_tty.c | ||
| nozomi.c | ||
| pty.c | ||
| rpmsg_tty.c | ||
| synclink_gt.c | ||
| sysrq.c | ||
| tty_audit.c | ||
| tty_baudrate.c | ||
| tty_buffer.c | ||
| tty_io.c | ||
| tty_ioctl.c | ||
| tty_jobctrl.c | ||
| tty_ldisc.c | ||
| tty_ldsem.c | ||
| tty_mutex.c | ||
| tty_port.c | ||
| tty.h | ||
| ttynull.c | ||
| vcc.c | ||