lkml.org 
[lkml]   [2010]   [Dec]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [patch] drivers: serial: apbuart: Handle OF failures gracefully
On Thu, Dec 16, 2010 at 01:06:35PM -0000, Thomas Gleixner wrote:
> 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 <mingo.elte.hu>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: Kristoffer Glembo <kristoffer@gaisler.com>
> Cc: Greg Kroah-Hartman <gregkh@suse.de>
>

Acked-by: Grant Likely <grant.likely@secretlab.ca>

> ---
> 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");
>
>


\
 
 \ /
  Last update: 2010-12-24 10:05    [W:0.033 / U:0.604 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site