From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: [PATCH 5/5] tty: serial: Add 8250-core based omap driver Date: Thu, 17 Jul 2014 09:42:19 +0200 Message-ID: <20140717074219.GA29193@linutronix.de> References: <1405521903-5877-1-git-send-email-bigeasy@linutronix.de> <1405521903-5877-6-git-send-email-bigeasy@linutronix.de> <20140717070859.GD18374@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from www.linutronix.de ([62.245.132.108]:33776 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753397AbaGQHmZ (ORCPT ); Thu, 17 Jul 2014 03:42:25 -0400 Content-Disposition: inline In-Reply-To: <20140717070859.GD18374@atomide.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Tony Lindgren Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Felipe Balbi , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Greg Kroah-Hartman * Tony Lindgren | 2014-07-17 00:09:00 [-0700]: >Seems to boot a bit further now with output from serial console >initially, then I'm getting the following error again that's probably >related to clocks not enabled when the registers are accessed: It is (mostly) the same thing as before. We have additionally omap_8250_startup() in the backtrace but it is the same thing. So you say I miss a clock? Looking through serial8250_do_startup() I see: - pm_runtime_get_sync(port->dev); which should get the clocks up - serial8250_clear_fifos() which does a write at address + 8. Seems to work. - serial_port_in(port, UART_LSR); does a read at address + 0x14, seems to work. - serial_port_in(port, UART_RX); does a read at address + 0. This is probably the bad one. Now comparing with omap-serial I noticed that I do a 32bit access instead a 16bit. Could you please try the following hack: diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 2e4a93b..94af5a3 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -420,13 +420,13 @@ static void mem_serial_out(struct uart_port *p, int offset, int value) static void mem32_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; - writel(value, p->membase + offset); + writew(value, p->membase + offset); } static unsigned int mem32_serial_in(struct uart_port *p, int offset) { offset = offset << p->regshift; - return readl(p->membase + offset); + return readw(p->membase + offset); } static unsigned int io_serial_in(struct uart_port *p, int offset) besides that, I don't see what could be different. >Regards, > >Tony Sebastian