linux-kernel - [PATCH] serial: liteuart: polling all interrupts in the IRQ process

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20250826081445.505947-1-inochiama@gmail.com>
Date: Tue, 26 Aug 2025 16:14:44 +0800
From: Inochi Amaoto <inochiama@...il.com>
To: Karol Gugala <kgugala@...micro.com>,
	Mateusz Holenko <mholenko@...micro.com>,
	Gabriel Somlo <gsomlo@...il.com>,
	Joel Stanley <joel@....id.au>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jirislaby@...nel.org>
Cc: Inochi Amaoto <inochiama@...il.com>,
	linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org,
	Yixun Lan <dlan@...too.org>,
	Longbin Li <looong.bin@...il.com>
Subject: [PATCH] serial: liteuart: polling all interrupts in the IRQ process

When using liteuart with aplic and imsic, the new interrupt will lost
if the interrupt handler can not handle all the data. This is simply
because the interrupt line will never be low, and the aplic will not
send the interrupt to imsic again.

Handle all data in the IRQ handler until no data incoming.

Signed-off-by: Inochi Amaoto <inochiama@...il.com>
---
 drivers/tty/serial/liteuart.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c
index 6429e8f11f36..436e8f06fb75 100644
--- a/drivers/tty/serial/liteuart.c
+++ b/drivers/tty/serial/liteuart.c
@@ -140,11 +140,17 @@ static irqreturn_t liteuart_interrupt(int irq, void *data)
 	 * irq[save|restore] spin_lock variants to cover all possibilities
 	 */
 	uart_port_lock_irqsave(port, &flags);
-	isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg;
-	if (isr & EV_RX)
-		liteuart_rx_chars(port);
-	if (isr & EV_TX)
-		liteuart_tx_chars(port);
+
+	isr = litex_read8(port->membase + OFF_EV_PENDING);
+
+	while (isr & uart->irq_reg) {
+		if (isr & EV_RX)
+			liteuart_rx_chars(port);
+		if (isr & EV_TX)
+			liteuart_tx_chars(port);
+		isr = litex_read8(port->membase + OFF_EV_PENDING);
+	}
+
 	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_RETVAL(isr);
-- 
2.51.0