From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755449Ab0LPNGx (ORCPT ); Thu, 16 Dec 2010 08:06:53 -0500 Received: from www.tglx.de ([62.245.132.106]:39996 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752454Ab0LPNGw (ORCPT ); Thu, 16 Dec 2010 08:06:52 -0500 Message-Id: <20101216124806.327116790@linutronix.de> User-Agent: quilt/0.48-1 Date: Thu, 16 Dec 2010 13:06:35 -0000 From: Thomas Gleixner To: LKML Cc: Grant Likely , Kristoffer Glembo , Greg Kroah-Hartman , Ingo Molnar Subject: [patch] drivers: serial: apbuart: Handle OF failures gracefully Content-Disposition: inline; filename=drivers-serial-apbuart-of-fix.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The apbuart driver depends on OF and relies on everything being available. So if it's probed on a platform which has OF support, but no device tree is available it crashes. Triggered by the upcoming x86 OF support in randconfig testing. Further it's inconsistent vs. the probing and exiting from the of_match loop. Make it robust and consistent: - check the availablility of OF nodes before dereferencing - return -ENODEV when the device tree lookup fails - return -ENODEV when no uart port configuration is found - return -ENODEV when invalid uart port configuration is found Remove the enum_done check while at it. Driver init functions are only called once. Remove the pointless vendor and device queries as well. Reported-by: Ingo Molnar Signed-off-by: Thomas Gleixner Cc: Grant Likely Cc: Kristoffer Glembo Cc: Greg Kroah-Hartman --- drivers/serial/apbuart.c | 48 ++++++++++++++++++----------------------------- 1 file changed, 19 insertions(+), 29 deletions(-) Index: linux-2.6-tip/drivers/serial/apbuart.c =================================================================== --- linux-2.6-tip.orig/drivers/serial/apbuart.c +++ linux-2.6-tip/drivers/serial/apbuart.c @@ -593,54 +593,44 @@ static struct of_platform_driver grlib_a }; -static void grlib_apbuart_configure(void) +static int grlib_apbuart_configure(void) { - static int enum_done; struct device_node *np, *rp; - struct uart_port *port = NULL; const u32 *prop; - int freq_khz; - int v = 0, d = 0; - unsigned int addr; - int irq, line; - struct amba_prom_registers *regs; - - if (enum_done) - return; + int freq_khz, line = 0; /* Get bus frequency */ rp = of_find_node_by_path("/"); + if (!rp) + return -ENODEV; rp = of_get_next_child(rp, NULL); + if (!rp) + return -ENODEV; prop = of_get_property(rp, "clock-frequency", NULL); + if (!prop) + return -ENODEV; freq_khz = *prop; - line = 0; for_each_matching_node(np, apbuart_match) { + const int *irqs = of_get_property(np, "interrupts", NULL); + const struct amba_prom_registers *regs; + struct uart_port *port; + unsigned long addr; - int *vendor = (int *) of_get_property(np, "vendor", NULL); - int *device = (int *) of_get_property(np, "device", NULL); - int *irqs = (int *) of_get_property(np, "interrupts", NULL); - regs = (struct amba_prom_registers *) - of_get_property(np, "reg", NULL); - - if (vendor) - v = *vendor; - if (device) - d = *device; + regs = of_get_property(np, "reg", NULL); if (!irqs || !regs) - return; + return -ENODEV; grlib_apbuart_nodes[line] = np; addr = regs->phys_addr; - irq = *irqs; port = &grlib_apbuart_ports[line]; port->mapbase = addr; port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map)); - port->irq = irq; + port->irq = *irqs; port->iotype = UPIO_MEM; port->ops = &grlib_apbuart_ops; port->flags = UPF_BOOT_AUTOCONF; @@ -652,12 +642,10 @@ static void grlib_apbuart_configure(void /* We support maximum UART_NR uarts ... */ if (line == UART_NR) break; - } - enum_done = 1; - grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line; + return line ? 0 : -ENODEV; } static int __init grlib_apbuart_init(void) @@ -665,7 +653,9 @@ static int __init grlib_apbuart_init(voi int ret; /* Find all APBUARTS in device the tree and initialize their ports */ - grlib_apbuart_configure(); + ret = grlib_apbuart_configure(); + if (ret) + return ret; printk(KERN_INFO "Serial: GRLIB APBUART driver\n");