From 56dde68f85be0a20935bb4ed996db7a7f68b3202 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 28 May 2021 10:58:49 +0200 Subject: 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 Cc: Jan Kiszka Cc: Vignesh Raghavendra Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index c71bd766fa56..8ac11eaeca51 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); -- cgit v1.2.3