From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Ulrich Hecht <uli+renesas@fpond.eu>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
linux-serial@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 117/176] serial: sh-sci: fix break handling for sysrq
Date: Thu, 9 Sep 2021 07:50:19 -0400 [thread overview]
Message-ID: <20210909115118.146181-117-sashal@kernel.org> (raw)
In-Reply-To: <20210909115118.146181-1-sashal@kernel.org>
From: Ulrich Hecht <uli+renesas@fpond.eu>
[ Upstream commit 87b8061bad9bd4b549b2daf36ffbaa57be2789a2 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/tty/serial/sh-sci.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 70898a999a49..f700bfaef129 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1760,6 +1760,10 @@ 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;
@@ -1839,7 +1843,8 @@ 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 */
--
2.30.2
prev parent reply other threads:[~2021-09-09 12:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210909115118.146181-1-sashal@kernel.org>
2021-09-09 11:48 ` [PATCH AUTOSEL 5.10 029/176] tty: serial: jsm: hold port lock when reporting modem line changes Sasha Levin
2021-09-09 11:49 ` [PATCH AUTOSEL 5.10 053/176] serial: 8250: Define RX trigger levels for OxSemi 950 devices Sasha Levin
2021-09-09 11:49 ` [PATCH AUTOSEL 5.10 056/176] serial: 8250_pci: make setup_port() parameters explicitly unsigned Sasha Levin
2021-09-09 11:49 ` [PATCH AUTOSEL 5.10 081/176] serial: 8250_omap: Handle optional overrun-throttle-ms property Sasha Levin
2021-09-09 11:50 ` Sasha Levin [this message]
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