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authorUlrich Hecht <uli+renesas@fpond.eu>2021-08-16 18:22:01 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-08-16 18:53:40 +0200
commit87b8061bad9bd4b549b2daf36ffbaa57be2789a2 (patch)
tree1565372a1fae10c7efdc8949acef3e80bea66e94
parent3d881e32e295decbc86f5d920bedae929be5bfb0 (diff)
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: Ulrich Hecht <uli+renesas@fpond.eu> Link: https://lore.kernel.org/r/20210816162201.28801-1-uli+renesas@fpond.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/sh-sci.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 07eb56294371..89ee43061d3a 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -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 */