hwmon: (w83781d) 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 makes the request
(and thus the detection) fail.

This fixes lm-sensors ticket #2306:
http://www.lm-sensors.org/ticket/2306

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

1 files changed, 16 insertions, 5 deletions

diff --git a/drivers/hwmon/w83781d.c b/drivers/hwmon/w83781d.c
index 5c85670e2d16..f942ecdd47c8 100644
--- a/drivers/hwmon/w83781d.c
+++ b/drivers/hwmon/w83781d.c
@@ -1367,7 +1367,8 @@ w83781d_isa_probe(struct platform_device *pdev)
 
         /* Reserve the ISA region */
         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
-        if (!request_region(res->start, W83781D_EXTENT, "w83781d")) {
+        if (!request_region(res->start + W83781D_ADDR_REG_OFFSET, 2,
+                            "w83781d")) {
                 err = -EBUSY;
                 goto exit;
         }
@@ -1415,7 +1416,7 @@ w83781d_isa_probe(struct platform_device *pdev)
         device_remove_file(&pdev->dev, &dev_attr_name);
         kfree(data);
  exit_release_region:
-        release_region(res->start, W83781D_EXTENT);
+        release_region(res->start + W83781D_ADDR_REG_OFFSET, 2);
  exit:
         return err;
 }
@@ -1429,7 +1430,7 @@ w83781d_isa_remove(struct platform_device *pdev)
         sysfs_remove_group(&pdev->dev.kobj, &w83781d_group);
         sysfs_remove_group(&pdev->dev.kobj, &w83781d_group_opt);
         device_remove_file(&pdev->dev, &dev_attr_name);
-        release_region(data->client.addr, W83781D_EXTENT);
+        release_region(data->client.addr + W83781D_ADDR_REG_OFFSET, 2);
         kfree(data);
 
         return 0;
@@ -1797,8 +1798,17 @@ w83781d_isa_found(unsigned short address)
 {
         int val, save, found = 0;
 
-        if (!request_region(address, W83781D_EXTENT, "w83781d"))
+        /* 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, "w83781d")) {
+                pr_debug("w83781d: Failed to request low part of region\n");
                 return 0;
+        }
+        if (!request_region(address + 4, 4, "w83781d")) {
+                pr_debug("w83781d: 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 W83781D-like
@@ -1871,7 +1881,8 @@ w83781d_isa_found(unsigned short address)
                         val == 0x30 ? "W83782D" : "W83781D", (int)address);
 
  release:
-        release_region(address, W83781D_EXTENT);
+        release_region(address + 4, 4);
+        release_region(address, 4);
         return found;
 }