hwmon: (lm78) Fix I/O resource conflict with PNP
Only request I/O ports 0x295-0x296 instead of the full I/O address
range. This solves a conflict with PNP resources on a few motherboards.
Also request the I/O ports in two parts (4 low ports, 4 high ports)
during device detection, otherwise the PNP resource make the request
(and thus the detection) fail.
This is the exact same fix that was applied to driver w83781d in
March 2008 to address the same problem:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=2961cb22ef02850d90e7a12c28a14d74e327df8d
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/lm78.c b/drivers/hwmon/lm78.c
index ed7859f..2c96d8a 100644
--- a/drivers/hwmon/lm78.c
+++ b/drivers/hwmon/lm78.c
@@ -655,7 +655,7 @@
/* Reserve the ISA region */
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
- if (!request_region(res->start, LM78_EXTENT, "lm78")) {
+ if (!request_region(res->start + LM78_ADDR_REG_OFFSET, 2, "lm78")) {
err = -EBUSY;
goto exit;
}
@@ -699,7 +699,7 @@
device_remove_file(&pdev->dev, &dev_attr_name);
kfree(data);
exit_release_region:
- release_region(res->start, LM78_EXTENT);
+ release_region(res->start + LM78_ADDR_REG_OFFSET, 2);
exit:
return err;
}
@@ -711,7 +711,7 @@
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&pdev->dev.kobj, &lm78_group);
device_remove_file(&pdev->dev, &dev_attr_name);
- release_region(data->client.addr, LM78_EXTENT);
+ release_region(data->client.addr + LM78_ADDR_REG_OFFSET, 2);
kfree(data);
return 0;
@@ -837,8 +837,17 @@
{
int val, save, found = 0;
- if (!request_region(address, LM78_EXTENT, "lm78"))
+ /* We have to request the region in two parts because some
+ boards declare base+4 to base+7 as a PNP device */
+ if (!request_region(address, 4, "lm78")) {
+ pr_debug("lm78: Failed to request low part of region\n");
return 0;
+ }
+ if (!request_region(address + 4, 4, "lm78")) {
+ pr_debug("lm78: Failed to request high part of region\n");
+ release_region(address, 4);
+ return 0;
+ }
#define REALLY_SLOW_IO
/* We need the timeouts for at least some LM78-like
@@ -901,7 +910,8 @@
val & 0x80 ? "LM79" : "LM78", (int)address);
release:
- release_region(address, LM78_EXTENT);
+ release_region(address + 4, 4);
+ release_region(address, 4);
return found;
}