From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from yw-out-2324.google.com (yw-out-2324.google.com [74.125.46.31]) by ozlabs.org (Postfix) with ESMTP id 7DF91DDFA3 for ; Fri, 29 May 2009 12:57:57 +1000 (EST) Received: by yw-out-2324.google.com with SMTP id 2so2680260ywt.39 for ; Thu, 28 May 2009 19:57:56 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 28 May 2009 23:57:55 -0300 Message-ID: Subject: Fwd: serial8250: too much work From: Alemao To: linuxppc-dev@ozlabs.org Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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@4500, interrupts =3D <9 =A00x8> serial1: serial@4600, interrupts =3D <10 0x8> spi: =A0 =A0 spi@7000, =A0 =A0 interrupts =3D <16 0x8> But when kernel starts: --- Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled serial8250.0: ttyS0 at MMIO 0xe0004500 (irq =3D 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: /* =A0* Digital did something really horribly wrong with the OUT1 and OUT2 =A0* lines on at least some ALPHA's. =A0The failure mode is that if either =A0* is cleared, the machine locks up with endless interrupts. =A0*/ /* =A0* WindRiver did something similarly broken on their SBC8560 board. The =A0* UART tristates its IRQ output while OUT2 is clear, but they pulled =A0* the interrupt line _up_ instead of down, so if we register the IRQ =A0* while the UART is in that state, we die in an IRQ storm. =A0*/ I also tried removing serial1 and spi from .dts, but didn't work. Any sugestions? Cheers, -- Alemao