rtc-cmos probe() cleanup
Some cleanups for the rtc-cmos probe logic:
- Claim i/o ports with request_region() not request_resource(),
for better coexistence betwen platform and pnp bus glues.
- Claim those ports earlier, to help work around procfs bugs
(it allows duplicate names, like /proc/driver/rtc).
- Fix some glitches in cleanup code, notably a cut'n'paste-o
where the i/o port region might not get released during
cleanup after a probe fault.
And some comment clarifications, including noting that this code
must work with PNPBIOS not just PNPACPI..
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 6d0c353..e3fe83a 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -433,6 +433,19 @@
if (!ports)
return -ENODEV;
+ /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
+ *
+ * REVISIT non-x86 systems may instead use memory space resources
+ * (needing ioremap etc), not i/o space resources like this ...
+ */
+ ports = request_region(ports->start,
+ ports->end + 1 - ports->start,
+ driver_name);
+ if (!ports) {
+ dev_dbg(dev, "i/o registers already in use\n");
+ return -EBUSY;
+ }
+
cmos_rtc.irq = rtc_irq;
cmos_rtc.iomem = ports;
@@ -454,24 +467,13 @@
cmos_rtc.rtc = rtc_device_register(driver_name, dev,
&cmos_rtc_ops, THIS_MODULE);
- if (IS_ERR(cmos_rtc.rtc))
- return PTR_ERR(cmos_rtc.rtc);
+ if (IS_ERR(cmos_rtc.rtc)) {
+ retval = PTR_ERR(cmos_rtc.rtc);
+ goto cleanup0;
+ }
cmos_rtc.dev = dev;
dev_set_drvdata(dev, &cmos_rtc);
-
- /* platform and pnp busses handle resources incompatibly.
- *
- * REVISIT for non-x86 systems we may need to handle io memory
- * resources: ioremap them, and request_mem_region().
- */
- if (is_pnp()) {
- retval = request_resource(&ioport_resource, ports);
- if (retval < 0) {
- dev_dbg(dev, "i/o registers already in use\n");
- goto cleanup0;
- }
- }
rename_region(ports, cmos_rtc.rtc->dev.bus_id);
spin_lock_irq(&rtc_lock);
@@ -534,9 +536,10 @@
return 0;
cleanup1:
- rename_region(ports, NULL);
-cleanup0:
+ cmos_rtc.dev = NULL;
rtc_device_unregister(cmos_rtc.rtc);
+cleanup0:
+ release_region(ports->start, ports->end + 1 - ports->start);
return retval;
}
@@ -555,19 +558,21 @@
static void __exit cmos_do_remove(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
+ struct resource *ports;
cmos_do_shutdown();
- if (is_pnp())
- release_resource(cmos->iomem);
- rename_region(cmos->iomem, NULL);
-
if (is_valid_irq(cmos->irq))
- free_irq(cmos->irq, cmos_rtc.rtc);
+ free_irq(cmos->irq, cmos->rtc);
- rtc_device_unregister(cmos_rtc.rtc);
+ rtc_device_unregister(cmos->rtc);
+ cmos->rtc = NULL;
- cmos_rtc.dev = NULL;
+ ports = cmos->iomem;
+ release_region(ports->start, ports->end + 1 - ports->start);
+ cmos->iomem = NULL;
+
+ cmos->dev = NULL;
dev_set_drvdata(dev, NULL);
}
@@ -654,7 +659,8 @@
/*----------------------------------------------------------------*/
/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems,
- * the device node will always be created as a PNPACPI device.
+ * the device node will always be created as a PNPACPI device. Plus
+ * pre-ACPI PCs probably list it in the PNPBIOS tables.
*/
#ifdef CONFIG_PNP