Commit 87b8061b authored by Ulrich Hecht's avatar Ulrich Hecht Committed by Greg Kroah-Hartman
Browse files

serial: sh-sci: fix break handling for sysrq 



This fixes two issues that cause the sysrq sequence to be inadvertently
aborted on SCIF serial consoles:

- a NUL character remains in the RX queue after a break has been detected,
  which is then passed on to uart_handle_sysrq_char()
- the break interrupt is handled twice on controllers with multiplexed ERI
  and BRI interrupts

Signed-off-by: default avatarUlrich Hecht <uli+renesas@fpond.eu>
Link: https://lore.kernel.org/r/20210816162201.28801-1-uli+renesas@fpond.eu


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3d881e32

drivers/tty/serial/sh-sci.c

+6 −1
Original line number Diff line number Diff line
@@ -1758,6 +1758,10 @@ static irqreturn_t sci_br_interrupt(int irq, void *ptr) 


	/* Handle BREAKs */

	sci_handle_breaks(port);



	/* drop invalid character received before break was detected */

	serial_port_in(port, SCxRDR);



	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));



	return IRQ_HANDLED;
@@ -1837,7 +1841,8 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) 
		ret = sci_er_interrupt(irq, ptr);



	/* Break Interrupt */

	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)

	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&

	    (ssr_status & SCxSR_BRK(port)) && err_enabled)

		ret = sci_br_interrupt(irq, ptr);



	/* Overrun Interrupt */