[PATCH] drivers/ide/ide-probe.c Skip ide_wait_not_busy on noprobe-disks. was: [PATCH][RESUBMIT] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Jonas Stare <jonas.stare@purplescout.se>]

There is a problem in some hardware where the kernel will stall for
35 seconds waiting for disks that dont exist. This patch will skip
waiting for the BSY-bit on ide-drives to go away if you set
hdx=noprobe as a kernel option and the disk is not marked
as 'present' (like when you set the geometry by hand).

If no noprobe-option is set the code will work (more or less) as the 
original but if set the code will skip the ide_wait_not_busy() for that 
drive. Even if there would be a drive there and it is still BSY 
afterwards it should not matter since it isn't probed for later.

(The code also honors the MAX_DRIVES variable instead of assuming that 
there will be two harddrives on the bus.)


Signed-off-by: Jonas Stare <jonas.stare@purplescout.se>

diff -u linux-2.6.23.1-orig/drivers/ide/ide-probe.c linux-2.6.23.1/drivers/ide/ide-probe.c 
--- linux-2.6.23.1-orig/drivers/ide/ide-probe.c 2007-10-12 18:43:44.000000000 +0200
+++ linux-2.6.23.1/drivers/ide/ide-probe.c      2007-11-16 10:26:23.000000000 +0100
@@ -643,6 +643,7 @@
 static int wait_hwif_ready(ide_hwif_t *hwif)
 {
        int rc;
+       int unit;
 
        printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name);
 
@@ -659,16 +660,25 @@
                return rc;
 
        /* Now make sure both master & slave are ready */
-       SELECT_DRIVE(&hwif->drives[0]);
-       hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
-       mdelay(2);
-       rc = ide_wait_not_busy(hwif, 35000);
-       if (rc)
-               return rc;
-       SELECT_DRIVE(&hwif->drives[1]);
-       hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
-       mdelay(2);
-       rc = ide_wait_not_busy(hwif, 35000);
+       for (unit = 0; unit < MAX_DRIVES; ++unit) {
+               /* Ignore disks that we will not probe for later. */
+               if (!hwif->drives[unit].noprobe ||
+                   hwif->drives[unit].present) {
+                       SELECT_DRIVE(&hwif->drives[unit]);
+                       hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
+                       mdelay(2);
+                       rc = ide_wait_not_busy(hwif, 35000);
+                       if (rc) {
+                               /* Exit function with master reselected */
+                               if (unit != 0)
+                                       SELECT_DRIVE(&hwif->drives[0]);
+                               return rc;
+                       }
+               } else {
+                       printk(KERN_DEBUG "Skip ide_wait_not_busy for %s:%d\n",
+                               hwif->name, unit);
+               }
+       }
 
        /* Exit function with master reselected (let's be sane) */
        SELECT_DRIVE(&hwif->drives[0]);