ide: ide.c 'clear' fix, update "ide=nodma" documentation

Documentation/kernel-parameters.txt
- ide=nodma is no longer valid.

drivers/ide/Kconfig
- The module is ide-core.ko not ide.

drivers/ide/ide.c
- It took me a while to figure out what the arguments %d.%d:%d to nodma
  module parameter ment, so I added a comment to each.
- Added a comment to each of the sscanf lines.
- There is a bug, if j is 0 it would previously clear all the other bits
  except the current device, changed in three different places.
  mask &= (1 << i) should be mask &= ~(1 << i).

Signed-off-by: David Fries <david@fries.net>
[bart: s/disk/device/ in ide.c, beautify patch description]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

3 files changed, 13 insertions, 6 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 319785b6dcb1..0ed3234125e3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -868,8 +868,10 @@ and is between 256 and 4096 characters. It is defined in the file
         icn=            [HW,ISDN]
                         Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
 
-        ide=            [HW] (E)IDE subsystem
-                        Format: ide=nodma or ide=doubler
+        ide-core.nodma= [HW] (E)IDE subsystem
+                        Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
+                        .vlb_clock .pci_clock .noflush .noprobe .nowerr .cdrom
+                        .chs .ignore_cable are additional options
                         See Documentation/ide/ide.txt.
 
         idebus=         [HW] (E)IDE subsystem - VLB/PCI bus speed
diff --git a/drivers/ide/Kconfig b/drivers/ide/Kconfig
index 3dad2299d9c5..e072903b12f0 100644
--- a/drivers/ide/Kconfig
+++ b/drivers/ide/Kconfig
@@ -46,7 +46,7 @@ menuconfig IDE
           SMART parameters from disk drives.
 
           To compile this driver as a module, choose M here: the
-          module will be called ide.
+          module will be called ide-core.ko.
 
           For further information, please read <file:Documentation/ide/ide.txt>.
 
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 258805da15c3..0920e3b0c962 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -337,6 +337,7 @@ static int ide_set_dev_param_mask(const char *s, struct kernel_param *kp)
         int a, b, i, j = 1;
         unsigned int *dev_param_mask = (unsigned int *)kp->arg;
 
+        /* controller . device (0 or 1) [ : 1 (set) | 0 (clear) ] */
         if (sscanf(s, "%d.%d:%d", &a, &b, &j) != 3 &&
             sscanf(s, "%d.%d", &a, &b) != 2)
                 return -EINVAL;
@@ -349,7 +350,7 @@ static int ide_set_dev_param_mask(const char *s, struct kernel_param *kp)
         if (j)
                 *dev_param_mask |= (1 << i);
         else
-                *dev_param_mask &= (1 << i);
+                *dev_param_mask &= ~(1 << i);
 
         return 0;
 }
@@ -392,6 +393,8 @@ static int ide_set_disk_chs(const char *str, struct kernel_param *kp)
 {
         int a, b, c = 0, h = 0, s = 0, i, j = 1;
 
+        /* controller . device (0 or 1) : Cylinders , Heads , Sectors */
+        /* controller . device (0 or 1) : 1 (use CHS) | 0 (ignore CHS) */
         if (sscanf(str, "%d.%d:%d,%d,%d", &a, &b, &c, &h, &s) != 5 &&
             sscanf(str, "%d.%d:%d", &a, &b, &j) != 3)
                 return -EINVAL;
@@ -407,7 +410,7 @@ static int ide_set_disk_chs(const char *str, struct kernel_param *kp)
         if (j)
                 ide_disks |= (1 << i);
         else
-                ide_disks &= (1 << i);
+                ide_disks &= ~(1 << i);
 
         ide_disks_chs[i].cyl  = c;
         ide_disks_chs[i].head = h;
@@ -469,6 +472,8 @@ static int ide_set_ignore_cable(const char *s, struct kernel_param *kp)
 {
         int i, j = 1;
 
+        /* controller (ignore) */
+        /* controller : 1 (ignore) | 0 (use) */
         if (sscanf(s, "%d:%d", &i, &j) != 2 && sscanf(s, "%d", &i) != 1)
                 return -EINVAL;
 
@@ -478,7 +483,7 @@ static int ide_set_ignore_cable(const char *s, struct kernel_param *kp)
         if (j)
                 ide_ignore_cable |= (1 << i);
         else
-                ide_ignore_cable &= (1 << i);
+                ide_ignore_cable &= ~(1 << i);
 
         return 0;
 }