Patchwork Fix multiple RTC detections on SUN4D

login
register
mail settings
Submitter oftedal
Date July 17, 2009, 11:48 p.m.
Message ID <Pine.LNX.4.64.0907180125270.7407@oizys.tordivel.org>
Download mbox | patch
Permalink /patch/29949/
State Changes Requested
Delegated to: David Miller
Headers show

Comments

oftedal - July 17, 2009, 11:48 p.m.
On SUN4D machines there is one RTC-chip located on each systemboard, when 
booting all of these will be probed. Registering a second RTC with the 
kernel fails, and breaks the rtc:
[    0.212000] kobject (f02625f0): tried to init an initialized object, somethi
[    0.212000] [f0141418 : platform_device_register+0x4/0x18 ] [f01edbc4 : cloc
[    0.216000] ------------[ cut here ]------------
[    0.216000] WARNING: at fs/sysfs/dir.c:487 sysfs_add_one+0x84/0xa4()
[    0.216000] sysfs: cannot create duplicate filename '/devices/platform/rtc-m
[    0.216000] Modules linked in:
[    0.216000] [f00c1988 : sysfs_add_one+0x84/0xa4 ] [f00c1f70 : create_dir+0x4
[    0.216000] ---[ end trace 139ce121c98e96c9 ]---
[    0.220000] kobject_add_internal failed for rtc-m48t59.0 with -EEXIST, don't
[    0.220000] [f013d568 : device_add+0xc8/0x610 ] [f014134c : platform_device_
[    0.220000] Registering RTC device failed

Later on in the boot the following happens:
[   23.116000] drivers/rtc/hctosys.c: unable to open rtc device (rtc0)

The suggested fix searches the supplied RTC node for a address properties 
which only one RTC per system appears to have and registers only this RTC 
with the kernel. (Tested on SS20/SUN4M and SS1000E/SUN4D)

Signed-off-by: Kjetil Oftedal <oftedal@gmail.com>

--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/arch/sparc/kernel/time_32.c b/arch/sparc/kernel/time_32.c
index 614ac7b..a902761 100644
--- a/arch/sparc/kernel/time_32.c
+++ b/arch/sparc/kernel/time_32.c
@@ -152,11 +152,27 @@  static int __devinit clock_probe(struct of_device *op, const struct of_device_id
  {
  	struct device_node *dp = op->node;
  	const char *model = of_get_property(dp, "model", NULL);
+	struct property *prop = dp->properties;
+	char addr_present = 0;

  	if (!model)
  		return -ENODEV;

+	/* The primary RTC has an address property */
+	while (prop != NULL) {
+		if (!strcmp(prop->name, "address")) {
+			addr_present = 1;
+			break;
+		}
+		prop = prop->next;
+	}
+
+	/* Only register the primary RTC chip */
+	if (!addr_present)
+		return -ENODEV;
+
  	m48t59_rtc.resource = &op->resource[0];
+
  	if (!strcmp(model, "mk48t02")) {
  		/* Map the clock register io area read-only */
  		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,