Commit 73f85a14 authored by Aaron Sierra's avatar Aaron Sierra Committed by Greg Kroah-Hartman
Browse files

serial: 8250_exar: Read INT0 from slave device, too

commit 60ab0faf upstream.

The sleep wake-up refactoring that I introduced in

  commit c7e1b405 ("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 2c0ac5b4

 ("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: default avatarAndy Shevchenko <>
Signed-off-by: default avatarAaron Sierra <>
Fixes: c7e1b405

 ("tty: serial: exar: Relocate sleep wake-up handling")
Reviewed-by: default avatarAndy Shevchenko <>
Cc: stable <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 47f7d1da
......@@ -433,7 +433,11 @@ 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);
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