Hi.
This week I ran into a strange hardware problem. During boot I got a 35
second delay while waiting for IDE-disks that weren't there to report
that they were not in a BSY state. The problem was most likely in the
hardware but this patch enables you to ignore waiting for disks by
setting hdX=noprobe (and not setting the geometry by hand) as a kernel
option.
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.
There are other ways to get around the "35-seconds-of-waiting-in-vain",
like actually fix the hardware, insert a second drive that works or
recompile the kernel with edd-support builtin (atleast I've seen that
solution on a forum) and possibly others. But this patch would allow
people to get Linux to boot quickly on wonky hardware without having to
recompile anything.
(The code also honors the MAX_DRIVES variable instead of assuming that
ther will be 2 drives on the bus.)
I will be happy for all the comments I can get. :) But be gentle, this
is my first patch...
Best regards
Jonas Stare
Signed-off-by: Jonas Stare <[email protected]>
--
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 2007-11-09
10:43:16.000000000 +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);
@@ -659,20 +660,24 @@
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].forced_geom) {
+ SELECT_DRIVE(&hwif->drives[unit]);
+ hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
+ mdelay(2);
+ rc = ide_wait_not_busy(hwif, 35000);
+ /* Exit function with master selected (let's be
sane) */
+ SELECT_DRIVE(&hwif->drives[0]);
+ if (rc)
+ 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]);
-
return rc;
}
-
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