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From: Arnd Bergmann <arnd@arndb.de>
To: stable@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>, Orson Zhai <orsonzhai@gmail.com>,
	Baolin Wang <baolin.wang@linaro.org>,
	Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Lanqing Liu <lanqing.liu@spreadtrum.com>,
	Chunyan Zhang <chunyan.zhang@spreadtrum.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Lanqing Liu <lanqing.liu@unisoc.com>,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [BACKPORT 4.4.y 23/25] serial: sprd: clear timeout interrupt only rather than all interrupts
Date: Fri, 22 Mar 2019 16:44:14 +0100	[thread overview]
Message-ID: <20190322154425.3852517-24-arnd@arndb.de> (raw)
In-Reply-To: <20190322154425.3852517-1-arnd@arndb.de>

From: Lanqing Liu <lanqing.liu@spreadtrum.com>

On Spreadtrum's serial device, nearly all of interrupts would be cleared
by hardware except timeout interrupt.  This patch removed the operation
of clearing all interrupt in irq handler, instead added an if statement
to check if the timeout interrupt is supposed to be cleared.

Wrongly clearing timeout interrupt would lead to uart data stay in rx
fifo, that means the driver cannot read them out anymore.

Signed-off-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 4350782570b919f254c1e083261a21c19fcaee90)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/tty/serial/sprd_serial.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
index 176f0a2bf9d9..c894eca57e73 100644
--- a/drivers/tty/serial/sprd_serial.c
+++ b/drivers/tty/serial/sprd_serial.c
@@ -63,6 +63,7 @@
 
 /* interrupt clear register */
 #define SPRD_ICLR		0x0014
+#define SPRD_ICLR_TIMEOUT	BIT(13)
 
 /* line control register */
 #define SPRD_LCR		0x0018
@@ -298,7 +299,8 @@ static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
 		return IRQ_NONE;
 	}
 
-	serial_out(port, SPRD_ICLR, ~0);
+	if (ims & SPRD_IMSR_TIMEOUT)
+		serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT);
 
 	if (ims & (SPRD_IMSR_RX_FIFO_FULL |
 		SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
-- 
2.20.0


  parent reply	other threads:[~2019-03-22 15:50 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-22 15:43 [BACKPORT 4.4.y 00/25] candidates from spreadtrum 4.4 product kernel Arnd Bergmann
2019-03-22 15:43 ` [BACKPORT 4.4.y 01/25] mmc: pwrseq: constify mmc_pwrseq_ops structures Arnd Bergmann
2019-03-26  1:08   ` Greg KH
2019-03-26  6:44     ` Julia Lawall
2019-03-26  8:11     ` Arnd Bergmann
2019-03-22 15:43 ` [BACKPORT 4.4.y 02/25] ALSA: compress: add support for 32bit calls in a 64bit kernel Arnd Bergmann
2019-03-26  1:09   ` Greg KH
2019-03-26  7:55     ` Arnd Bergmann
2019-03-30  9:40       ` Greg KH
2019-03-22 15:43 ` [BACKPORT 4.4.y 03/25] mmc: pwrseq_simple: Make reset-gpios optional to match doc Arnd Bergmann
2019-03-22 15:43 ` [BACKPORT 4.4.y 04/25] USB: iowarrior: fix oops with malicious USB descriptors Arnd Bergmann
2019-03-26  1:13   ` Greg Kroah-Hartman
2019-03-26  8:20     ` Arnd Bergmann
2019-03-26  9:35       ` Baolin Wang
2019-03-26  9:47         ` 翟京 (Orson Zhai)
2019-03-22 15:43 ` [BACKPORT 4.4.y 05/25] mmc: debugfs: Add a restriction to mmc debugfs clock setting Arnd Bergmann
2019-03-22 15:43 ` [BACKPORT 4.4.y 06/25] mmc: make MAN_BKOPS_EN message a debug Arnd Bergmann
2019-03-22 15:43 ` [BACKPORT 4.4.y 07/25] mmc: sanitize 'bus width' in debug output Arnd Bergmann
2019-03-22 15:43 ` [BACKPORT 4.4.y 08/25] mmc: core: shut up "voltage-ranges unspecified" pr_info() Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 09/25] usb: dwc3: gadget: Fix suspend/resume during device mode Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 10/25] arm64: mm: Add trace_irqflags annotations to do_debug_exception() Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 11/25] mmc: core: fix using wrong io voltage if mmc_select_hs200 fails Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 12/25] mm/rmap: replace BUG_ON(anon_vma->degree) with VM_WARN_ON Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 13/25] extcon: usb-gpio: Don't miss event during suspend/resume Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 14/25] kbuild: setlocalversion: print error to STDERR Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 15/25] usb: gadget: composite: fix dereference after null check coverify warning Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 16/25] usb: gadget: Add the gserial port checking in gs_start_tx() Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 17/25] mmc: core: don't try to switch block size for dual rate mode Arnd Bergmann
2019-03-26  1:27   ` Greg KH
2019-03-26  8:14     ` Arnd Bergmann
2019-03-22 15:44 ` [BACKPORT 4.4.y 18/25] tcp/dccp: drop SYN packets if accept queue is full Arnd Bergmann
2019-03-26  1:21   ` Greg KH
2019-03-22 15:44 ` [BACKPORT 4.4.y 19/25] serial: sprd: adjust TIMEOUT to a big value Arnd Bergmann
2019-03-26  1:21   ` Greg KH
2019-03-22 15:44 ` [BACKPORT 4.4.y 20/25] Hang/soft lockup in d_invalidate with simultaneous calls Arnd Bergmann
2019-03-26  1:30   ` Greg KH
2019-03-22 15:44 ` [BACKPORT 4.4.y 21/25] arm64: traps: disable irq in die() Arnd Bergmann
2019-03-26  1:31   ` Greg KH
2019-03-22 15:44 ` [BACKPORT 4.4.y 22/25] usb: renesas_usbhs: gadget: fix unused-but-set-variable warning Arnd Bergmann
2019-03-22 15:44 ` Arnd Bergmann [this message]
2019-03-26  1:34   ` [BACKPORT 4.4.y 23/25] serial: sprd: clear timeout interrupt only rather than all interrupts Greg KH
2019-03-22 15:44 ` [BACKPORT 4.4.y 24/25] lib/int_sqrt: optimize small argument Arnd Bergmann
2019-03-26  1:36   ` Greg KH
2019-03-22 15:44 ` [BACKPORT 4.4.y 25/25] USB: core: only clean up what we allocated Arnd Bergmann
2019-03-26  1:36   ` Greg Kroah-Hartman
2019-03-26  2:18 ` [BACKPORT 4.4.y 00/25] candidates from spreadtrum 4.4 product kernel Greg KH

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