Re: [git patches] libata fixes

[Tejun Heo <htejun@gmail.com>]

Hello, Linus.

Linus Torvalds wrote:
> On Sun, 11 Mar 2007, Paul Rolland wrote:
>> My machine is having two problems : the one you are describing above,
>> which is due to a SIL controler being connected to one port of the ICH7
>> (at least, it seems to), and probing it goes  timeout, but nothing is
>> connected on it.
> 
> Ok, so that's just a message irritation, not actually bothersome 
> otherwise?

It involves a long timeout, so it's bothersome.  This is caused by
Silicon Image 4726/3726 storage processor (SATA Port Multiplier with
extra features) attached to one of the ICH ports.

If the first  downstream port in the PMP is empty and it gets reset in
non-PMP way, it identifies itself as "Config Disk" of quite small size.
 It's probably used to configure the extra features using standard ATA
RW commands.  Anyways, this "Config Disk" is a bit peculiar and doesn't
work very well with the current ATA reset sequence and gets identified
only after a few failures thus causing long timeout.

I keep forgetting about this.  I'll ask SIMG how to deal with this.  For
the time being, connecting a device to the PMP port should remove the
timeouts.

>> The second problem is a Jmicron363 controler that is failing to detect
>> the DVD-RW that is connected, unless I use the irqpoll option as Tejun has
>> suggested.
> 
> .. and this one has never worked without irqpoll?
> 
>> But, as you suggest it, I'm adding pci=nomsi to the command line....
>> rebooting... no change for this part of the problem.
>>
>> OK, the /proc/interrupt for this config, and the dmesg attached.
>>
>> 3 [23:22] rol@riri:~> cat /proc/interrupts 
>>            CPU0       CPU1       
>>   0:     297549          0   IO-APIC-edge      timer
>>   1:          7          0   IO-APIC-edge      i8042
>>   4:         13          0   IO-APIC-edge      serial
>>   6:          5          0   IO-APIC-edge      floppy
>>   8:          1          0   IO-APIC-edge      rtc
>>   9:          0          0   IO-APIC-fasteoi   acpi
>>  12:        126          0   IO-APIC-edge      i8042
>>  14:       8313          0   IO-APIC-edge      libata
>>  15:          0          0   IO-APIC-edge      libata
>>  16:          0          0   IO-APIC-fasteoi   eth1, libata
> 
> So it's the irq16 one that is the Jmicron controller and just isn't 
> getting any interrupts?
> 
> Since all the other interrupts work (and MSI worked for other 
> controllers), I don't think it's interrupt-routing related. Especially as 
> MSI shouldn't even care about things like that.
> 
> And since it all works when "irqpoll" is used, that implies that the 
> *only* thing that is broken is literally irq delivery.
> 
> Is there possibly some jmicron-specific "enable interrupts" bit? 

(cc'ing Justin of JMicron.  Hello, please correct me if I'm wrong.)

Not that I know of.  The PATA portion of JMB controllers is bog standard
PCI BMDMA ATA device where ATA_NIEN is the way to turn IRQ on and off.

Thanks.

-- 
tejun