2.6.28: Is there a way to disable sata probing for certain ports?

2.6.28: Is there a way to disable sata probing for certain ports?

[Justin Piszcz]

When I boot from an Intel X25-E SSD, it takes roughly a few seconds; 
however, items such as:

$ dmesg|grep link\ down
[    2.447030] ata4: SATA link down (SStatus 0 SControl 300)
[    4.481288] ata5: SATA link down (SStatus 0 SControl 0)
[    6.501288] ata6: SATA link down (SStatus 0 SControl 0)
[    8.522038] ata7: SATA link down (SStatus 0 SControl 0)
[   10.552288] ata8: SATA link down (SStatus 0 SControl 0)

Scanning for devices on channels that have nothing connected adds to the 
boot time, is there anyway to turn off/disable scanning for certain ports 
to help speed the boot process?

Re: 2.6.28: Is there a way to disable sata probing for certain ports?

[Grant Grundler]

On Tue, Dec 30, 2008 at 4:24 AM, Justin Piszcz <jpiszcz@lucidpixels.com> wrote:
> When I boot from an Intel X25-E SSD, it takes roughly a few seconds;
> however, items such as:
>
> $ dmesg|grep link\ down
> [    2.447030] ata4: SATA link down (SStatus 0 SControl 300)
> [    4.481288] ata5: SATA link down (SStatus 0 SControl 0)
> [    6.501288] ata6: SATA link down (SStatus 0 SControl 0)
> [    8.522038] ata7: SATA link down (SStatus 0 SControl 0)
> [   10.552288] ata8: SATA link down (SStatus 0 SControl 0)
>
> Scanning for devices on channels that have nothing connected adds to the
> boot time, is there anyway to turn off/disable scanning for certain ports to
> help speed the boot process?

Some BIOSs allow one to enable/disable each port individually.
Have you checked the BIOS config menus for such an option?

drivers/ata/libata-core.c declares "ata_force_param_buf" but I don't
see any documentation for it despite the reference to
Documentation/kernel-parameters.txt .

hth,
grant

Re: 2.6.28: Is there a way to disable sata probing for certain ports?

[Alan Jenkins]

On Tue, Dec 30, 2008 at 5:08 PM, Grant Grundler <grundler@google.com> wrote:
> On Tue, Dec 30, 2008 at 4:24 AM, Justin Piszcz <jpiszcz@lucidpixels.com> wrote:
>> When I boot from an Intel X25-E SSD, it takes roughly a few seconds;
>> however, items such as:
>>
>> $ dmesg|grep link\ down
>> [    2.447030] ata4: SATA link down (SStatus 0 SControl 300)
>> [    4.481288] ata5: SATA link down (SStatus 0 SControl 0)
>> [    6.501288] ata6: SATA link down (SStatus 0 SControl 0)
>> [    8.522038] ata7: SATA link down (SStatus 0 SControl 0)
>> [   10.552288] ata8: SATA link down (SStatus 0 SControl 0)
>>
>> Scanning for devices on channels that have nothing connected adds to the
>> boot time, is there anyway to turn off/disable scanning for certain ports to
>> help speed the boot process?
>
> Some BIOSs allow one to enable/disable each port individually.
> Have you checked the BIOS config menus for such an option?
>
> drivers/ata/libata-core.c declares "ata_force_param_buf" but I don't
> see any documentation for it despite the reference to
> Documentation/kernel-parameters.txt .

There is.  Search the file for "libata.force".  But it doesn't support
disabling the scan for specific ports; that has yet to be implemented.

<https://kerneltrap.org/mailarchive/linux-kernel/2008/8/11/2900064/thread>

Alan

Re: 2.6.28: Is there a way to disable sata probing for certain ports?

[Justin Piszcz]

On Tue, 30 Dec 2008, Grant Grundler wrote:

> On Tue, Dec 30, 2008 at 4:24 AM, Justin Piszcz <jpiszcz@lucidpixels.com> wrote:
>> When I boot from an Intel X25-E SSD, it takes roughly a few seconds;
>> however, items such as:
>>
>> $ dmesg|grep link\ down
>> [    2.447030] ata4: SATA link down (SStatus 0 SControl 300)
>> [    4.481288] ata5: SATA link down (SStatus 0 SControl 0)
>> [    6.501288] ata6: SATA link down (SStatus 0 SControl 0)
>> [    8.522038] ata7: SATA link down (SStatus 0 SControl 0)
>> [   10.552288] ata8: SATA link down (SStatus 0 SControl 0)
>>
>> Scanning for devices on channels that have nothing connected adds to the
>> boot time, is there anyway to turn off/disable scanning for certain ports to
>> help speed the boot process?
>
> Some BIOSs allow one to enable/disable each port individually.
> Have you checked the BIOS config menus for such an option?
>
> drivers/ata/libata-core.c declares "ata_force_param_buf" but I don't
> see any documentation for it despite the reference to
> Documentation/kernel-parameters.txt .
>
> hth,
> grant
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Disabling the additional controllers helped a bit but for AHCI on a few 
boards its all or nothing, AHCI enabled/disabled.

Justin.