From 56dde68f85be0a20935bb4ed996db7a7f68b3202 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 28 May 2021 10:58:49 +0200
Subject: [PATCH] Revert "serial: 8250: 8250_omap: Fix possible interrupt
storm"
This reverts commit 31fae7c8b18c3f8029a2a5dce97a3182c1a167a0.
Tony writes:
I just noticed this causes the following regression in Linux
next when pressing a key on uart console after boot at least on
omap3. This seems to happen on serial_port_in(port, UART_RX) in
the quirk handling.
So let's drop this.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/YLCCJzkkB4N7LTQS@atomide.com
Fixes: 31fae7c8b18c ("serial: 8250: 8250_omap: Fix possible interrupt storm")
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/8250/8250_omap.c | 12 ------------
1 file changed, 12 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index c71bd766fa564..8ac11eaeca51b 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -104,9 +104,6 @@
#define UART_OMAP_EFR2 0x23
#define UART_OMAP_EFR2_TIMEOUT_BEHAVE BIT(6)
-/* RX FIFO occupancy indicator */
-#define UART_OMAP_RX_LVL 0x64
-
struct omap8250_priv {
int line;
u8 habit;
@@ -628,15 +625,6 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
serial8250_rpm_get(up);
iir = serial_port_in(port, UART_IIR);
ret = serial8250_handle_irq(port, iir);
- /*
- * It is possible that RX TIMEOUT is signalled after FIFO
- * has been drained, in which case a dummy read of RX FIFO is
- * required to clear RX TIMEOUT condition.
- */
- if ((iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT) {
- if (serial_port_in(port, UART_OMAP_RX_LVL) == 0)
- serial_port_in(port, UART_RX);
- }
serial8250_rpm_put(up);
return IRQ_RETVAL(ret);
--
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