From da93a03fdd0a40ed91568434fade58d9043be20e Mon Sep 17 00:00:00 2001 From: Aaron Sierra Date: Tue, 24 Jul 2018 14:23:46 -0500 Subject: [PATCH] serial: 8250_exar: Read INT0 from slave device, too commit 60ab0fafc4b652fcaf7cbc3bb8555a0cf1149c28 upstream. The sleep wake-up refactoring that I introduced in commit c7e1b4059075 ("tty: serial: exar: Relocate sleep wake-up handling") did not account for devices with a slave device on the expansion port. This patch pokes the INT0 register in the slave device, if present, in order to ensure that MSI interrupts don't get permanently "stuck" because of a sleep wake-up interrupt as described here: commit 2c0ac5b48a35 ("serial: exar: Fix stuck MSIs") This also converts an ioread8() to readb() in order to provide visual consistency with the MMIO-only accessors used elsewhere in the driver. Reported-by: Andy Shevchenko Signed-off-by: Aaron Sierra Fixes: c7e1b4059075 ("tty: serial: exar: Relocate sleep wake-up handling") Reviewed-by: Andy Shevchenko Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_exar.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c index e0aa5f03004c..411b4b03457b 100644 --- a/drivers/tty/serial/8250/8250_exar.c +++ b/drivers/tty/serial/8250/8250_exar.c @@ -436,7 +436,11 @@ static irqreturn_t exar_misc_handler(int irq, void *data) struct exar8250 *priv = data; /* Clear all PCI interrupts by reading INT0. No effect on IIR */ - ioread8(priv->virt + UART_EXAR_INT0); + readb(priv->virt + UART_EXAR_INT0); + + /* Clear INT0 for Expansion Interface slave ports, too */ + if (priv->board->num_ports > 8) + readb(priv->virt + 0x2000 + UART_EXAR_INT0); return IRQ_HANDLED; } -- 2.20.1