Fwd: serial8250: too much work

[Alemao]

Im facing some problems with serial, getting flooded with this
message:

---
serial8250: too much work for irq16
---

Something I notice, in my .dts I have the following lines:

serial0: serial at 4500, interrupts = <9  0x8>
serial1: serial at 4600, interrupts = <10 0x8>
spi:       spi at 7000,      interrupts = <16 0x8>

But when kernel starts:

---
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
serial8250.0: ttyS0 at MMIO 0xe0004500 (irq = 16) is a 16550A
---

Why IRQ 16? Shouldn't it be IRQ 9?

I traced functions calls in 8250.c driver:

---
serial8250_interrup() -> serial8250_handle_port() -> transmit_chars()
---

"too much work" is for transmiting, but there's nothing to transmit.

In my MPC8343 board I have only serial0 connected to a MAX3232, serial1
is floating. Maybe some electromagnetic interference in the bus?

I found this comments in linux/drivers/serial/8250.h, and tried to use
same defines that they used, but no success:

/*
 * Digital did something really horribly wrong with the OUT1 and OUT2
 * lines on at least some ALPHA's.  The failure mode is that if either
 * is cleared, the machine locks up with endless interrupts.
 */

/*
 * WindRiver did something similarly broken on their SBC8560 board. The
 * UART tristates its IRQ output while OUT2 is clear, but they pulled
 * the interrupt line _up_ instead of down, so if we register the IRQ
 * while the UART is in that state, we die in an IRQ storm.
 */


I also tried removing serial1 and spi from .dts, but didn't work.

Any sugestions?

Cheers,

--
Alemao