From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: Early serial port problems Date: Wed, 30 Mar 2005 10:41:10 +0100 Message-ID: <20050330104110.D6239@flint.arm.linux.org.uk> References: <5895.1109773145@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([212.18.232.186]:62226 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S261827AbVC3JlN (ORCPT ); Wed, 30 Mar 2005 04:41:13 -0500 Content-Disposition: inline In-Reply-To: <5895.1109773145@redhat.com>; from dhowells@redhat.com on Wed, Mar 02, 2005 at 02:19:05PM +0000 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: David Howells Cc: linux-serial@vger.kernel.org On Wed, Mar 02, 2005 at 02:19:05PM +0000, David Howells wrote: > (2) The boot console log lines for the serial ports and the proc tty listing > show an address of 0 because __frv_uart0.mapbase and __frv_uart1.mapbase > aren't set: > > Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled > ttyS0 at MMIO 0x0 (irq = 1) is a 16550A > ttyS1 at MMIO 0x0 (irq = 2) is a 16550A > io scheduler noop registered > > If I set .mapbase as well as .membase before calling early_serial_setup(), > then I see the kernel console output appear, but userspace can't access > the serial ports, and the serial driver doesn't record the existence of > the ports in the console log: > > Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled > io scheduler noop registered > > Adding in UPF_IOREMAP makes no difference. > > Unsetting .membase and just leaving .mapbase set and UPF_IOREMAP set means > that you don't even get kernel console output, though the kernel still > boots. > > I wonder if (1) is related to (2). Don't think so. It sounds like a problem with claiming the MMIO resources. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core