Re: [PATCH] drivers/ide/ide-probe.c, kernel 2.6.23.1

Re: [PATCH] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Jonas Stare]

Hi, thanks for the reply. :)

Bartlomiej Zolnierkiewicz wrote:
> Hi,
> 
> On Monday 12 November 2007, Andrew Morton wrote:
>> On Fri, 09 Nov 2007 11:22:41 +0100 Jonas Stare <jonas.stare@purplescout.se> wrote:
>>
>>> 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 
> 
> With what chipset and host driver does this happen?

I am not sure about the chip-set but I think it was vt82c686b. It used 
the via82cxxx-driver, but only _after_ using the generic ide-code to 
probe/wait (a long time) for the disks. (This was in Suse 10.1 SP 1.)

>>> 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 keep on hearing about problems with boot-time IDE probing.  It's public
>> enemy #1 with the embedded guys.
> 
> The problem is that we are not hearing about them.
> 
> Please forward the reports to linux-ide@vger.kernel.org.
> 
>> It does seem that operator intervention is needed in some fashion.
>>
>>> I will be happy for all the comments I can get. :) But be gentle, this 
>>> is my first patch...
> 
> Jonas, could you also put printk() dumping content of 'stat' in
> ide-iops.c::ide_wait_not_busy() so we can verify that it is not
> some problem with ide_wait_not_busy() itself.
> 

Sorry. :( I don't have access to the hardware anymore (which is a 
"home-made" embedded machine). But from what I could get from poking 
around was that the BSY-bit on the slave (that never has or ever will 
exists) was set, probably because those who built the thing wanted to 
save money and/or space on that "billionth of a cent"-resistor that Alan 
Cox talked about.

>>>    Best regards
>>>    Jonas Stare
>>>
>>> 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      2007-11-09 
>>> 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;
>>>
> 
> Hmm, so the first ide_wait_not_busy() (for the currently
> selected device) is OK and doesn't stall?
> 

It didn't stall for me... But even if it had, probe_hwif() will ignore 
the entire controller if you set "idex=noprobe".

(From drivers/ide/ide-probe.c)

static void probe_hwif(ide_hwif_t *hwif, void (*fixup)(ide_hwif_t *hwif))
{
         unsigned int unit;
         unsigned long flags;
         unsigned int irqd;

         if (hwif->noprobe)
                 return;


>>>          /* 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) {
> 
> It is better to check for ->present
> (->forced_geom implies that ->present is set).
> 

Great comment. :) I'll change that right away...

>>> +                       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]);
> 
> This changes the previous behavior adding an extra SELECT_DRIVE()
> before trying the slave drive.
> 

Mmmm, yes, I know. But I couldn't come up with a clean and nice way to 
be sure that the first drive is selected. Maybe I could move it inside 
the if-statement below?

>>> +                       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;
>>>   }
>> Maybe that's the fix, maybe not - I'll defer to others on that (please).
>>
>> Your email client is wordwrapping the text, and replaces tabs with spaces. 
>> Most of them seem to do this nowadays.  For thunderbird, please see
>> http://mbligh.org/linuxdocs/Email/Clients/Thunderbird
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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Re: [PATCH] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Bartlomiej Zolnierkiewicz]

Hi,

On Thursday 15 November 2007, Jonas Stare wrote:
> Hi, thanks for the reply. :)
> 
> Bartlomiej Zolnierkiewicz wrote:
> > Hi,
> > 
> > On Monday 12 November 2007, Andrew Morton wrote:
> >> On Fri, 09 Nov 2007 11:22:41 +0100 Jonas Stare <jonas.stare@purplescout.se> wrote:
> >>
> >>> 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 
> > 
> > With what chipset and host driver does this happen?
> 
> I am not sure about the chip-set but I think it was vt82c686b. It used 
> the via82cxxx-driver, but only _after_ using the generic ide-code to 
> probe/wait (a long time) for the disks. (This was in Suse 10.1 SP 1.)

AFAIK this means kernel version 2.6.16.xx.

If this is the case maybe the underlying problem has been already fixed
(but it doesn't mean that your patch is not worth applying, quite the
contrary).

> >>> 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 keep on hearing about problems with boot-time IDE probing.  It's public
> >> enemy #1 with the embedded guys.
> > 
> > The problem is that we are not hearing about them.
> > 
> > Please forward the reports to linux-ide@vger.kernel.org.
> > 
> >> It does seem that operator intervention is needed in some fashion.
> >>
> >>> I will be happy for all the comments I can get. :) But be gentle, this 
> >>> is my first patch...
> > 
> > Jonas, could you also put printk() dumping content of 'stat' in
> > ide-iops.c::ide_wait_not_busy() so we can verify that it is not
> > some problem with ide_wait_not_busy() itself.
> > 
> 
> Sorry. :( I don't have access to the hardware anymore (which is a 
> "home-made" embedded machine). But from what I could get from poking 
> around was that the BSY-bit on the slave (that never has or ever will 
> exists) was set, probably because those who built the thing wanted to 
> save money and/or space on that "billionth of a cent"-resistor that Alan 
> Cox talked about.
> 
> >>>    Best regards
> >>>    Jonas Stare
> >>>
> >>> 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      2007-11-09 
> >>> 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;
> >>>
> > 
> > Hmm, so the first ide_wait_not_busy() (for the currently
> > selected device) is OK and doesn't stall?
> > 
> 
> It didn't stall for me... But even if it had, probe_hwif() will ignore 
> the entire controller if you set "idex=noprobe".
> 
> (From drivers/ide/ide-probe.c)
> 
> static void probe_hwif(ide_hwif_t *hwif, void (*fixup)(ide_hwif_t *hwif))
> {
>          unsigned int unit;
>          unsigned long flags;
>          unsigned int irqd;
> 
>          if (hwif->noprobe)
>                  return;
> 
> 
> >>>          /* 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) {
> > 
> > It is better to check for ->present
> > (->forced_geom implies that ->present is set).
> > 
> 
> Great comment. :) I'll change that right away...
> 
> >>> +                       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]);
> > 
> > This changes the previous behavior adding an extra SELECT_DRIVE()
> > before trying the slave drive.
> > 
> 
> Mmmm, yes, I know. But I couldn't come up with a clean and nice way to 
> be sure that the first drive is selected. Maybe I could move it inside 
> the if-statement below?

Then the code will miss re-selecting master drive after waiting for
slave one if there were no problems (rc == 0).

What about adding "if (unit)" statement before SELECT_DRIVE() call?

> >>> +                       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;
> >>>   }
> >> Maybe that's the fix, maybe not - I'll defer to others on that (please).
> >>
> >> Your email client is wordwrapping the text, and replaces tabs with spaces. 
> >> Most of them seem to do this nowadays.  For thunderbird, please see
> >> http://mbligh.org/linuxdocs/Email/Clients/Thunderbird

Please fix the issues + wordwrapping and resubmit.

Thanks,
Bart

Re: [PATCH][RESUBMIT] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Jonas Stare]

Resubmit of IDE-probing-patch. It now checks hwif->drives[unit].present instead of
forced_geom and there is also an if-statement so it doesn't change back to the master
unless it have to. I choose to put it inside the if-statement that checks the return
code from ide_wait_not_busy, since it shouldn't revert back to the master drive unless
something is wrong and we have to leave the function. (I also left the old SELECT_DRIVE
after the for-loop so that we will select the master if everything is ok.) Inside the
if-statement or not makes not big difference until you get more than two drives on the
ide-bus...but this code should be ready for it. :)

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]);

Re: [PATCH][RESUBMIT] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Sergei Shtylyov]

Jonas Stare wrote:

> 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) {

    Why not:

		if (hwif->drives[unit].noprobe || !hwif->drives[unit].present) {
                 	printk(KERN_DEBUG "Skip ide_wait_not_busy for %s:%d\n",
                                hwif->name, unit);
			continue;
		}
                 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;
         	}
	}
>  
>         /* Exit function with master reselected (let's be sane) */
>         SELECT_DRIVE(&hwif->drives[0]);

MBR, Sergei

Re: [PATCH][RESUBMIT] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Jonas Stare]

Sergei Shtylyov wrote:
> Jonas Stare wrote:
> 
>> 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) {
> 
>    Why not:
> 
>         if (hwif->drives[unit].noprobe || !hwif->drives[unit].present) {
>                     printk(KERN_DEBUG "Skip ide_wait_not_busy for %s:%d\n",
>                                hwif->name, unit);
>             continue;
>         }
>                 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;
>             }
>     }

Hmmm, I was rather fond of my "wait for the disk unless we are specifically told not to"
rather than "don't check unless there might be a disk there". ...on the other hand
thats not what my comment said. :)

>>  
>>         /* Exit function with master reselected (let's be sane) */
>>         SELECT_DRIVE(&hwif->drives[0]);
> 
> MBR, Sergei

Re: [PATCH][RESUBMIT] drivers/ide/ide-probe.c, kernel 2.6.23.1

[Bartlomiej Zolnierkiewicz]

On Friday 16 November 2007, Jonas Stare wrote:
> Resubmit of IDE-probing-patch. It now checks hwif->drives[unit].present instead of
> forced_geom and there is also an if-statement so it doesn't change back to the master
> unless it have to. I choose to put it inside the if-statement that checks the return
> code from ide_wait_not_busy, since it shouldn't revert back to the master drive unless
> something is wrong and we have to leave the function. (I also left the old SELECT_DRIVE
> after the for-loop so that we will select the master if everything is ok.) Inside the
> if-statement or not makes not big difference until you get more than two drives on the
> ide-bus...but this code should be ready for it. :)
> 
> Signed-off-by: Jonas Stare <jonas.stare@purplescout.se>

Patch looks fine (thanks for fixing it) but please replace the changelog
above with the proper patch description (more like in your first mail which
contained the description of the problem encountered and of the solution,
also please try to keep it within 80-columns limit) - for git history patch
changelog is not really that interesting/valuable.

PS patch summary ("Subject:") may also be improved while at it - it should
describe the main goal of the patch, also since patch will be applied to
the current git tree giving the kernel version is not necessary.

Bart

[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]

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]);

Re: [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

[Bartlomiej Zolnierkiewicz]

On Friday 16 November 2007, Jonas Stare wrote:
> 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>

Thanks!

PS There were still some whitespace problems (all tabs were replaced by
spaces) so I just applied it by hand (and made few minor cleanups while
at it).

Bart