Hello, Thomas. Thomas Renninger wrote: > On Fri, 2007-02-23 at 02:08 -0800, Andrew Morton wrote: >> I'm starting to think that big acpi merge came a bit too soon. >> >> Begin forwarded message: >> >> Date: Thu, 22 Feb 2007 15:29:42 +0200 (EET) >> From: Meelis Roos <mroos@xxxxxxxx> >> To: Linux Kernel list <linux-kernel@xxxxxxxxxxxxxxx> >> Subject: ata-piix ACPI errors >> >> >> Testbooted 2.6.21-rc1+todays git on a PC with Intel 845 chipset and PATA >> HDD. Works fine but I now have these ACPI errors in dmesg, maybe someone >> is interested: >> >> ata_piix 0000:00:1f.1: version 2.00ac7 >> PCI: Enabling device 0000:00:1f.1 (0005 -> 0007) >> ACPI: PCI Interrupt 0000:00:1f.1[A] -> GSI 18 (level, low) -> IRQ 18 >> PCI: Setting latency timer of device 0000:00:1f.1 to 64 >> ata1: PATA max UDMA/100 cmd 0x000101f0 ctl 0x000103f6 bmdma 0x0001ffa0 irq 14 >> ata2: PATA max UDMA/100 cmd 0x00010170 ctl 0x00010376 bmdma 0x0001ffa8 irq 15 >> scsi0 : ata_piix >> ACPI Error (dsopcode-0481): Attempt to CreateField of length zero [20070126] > > I expect this to be ACPI (interpreter) unrelated and the bug should be > in drivers/ata/libata-acpi.c. > The problem is that libata-acpi.c calls _GTF function before _STM has > been called. This is forbidden by ACPI spec. I can't find such wording in acpi 3.0a spec. It says _STM may make adjustments to the result of _GTF. Hmmm... the suspend/resume order does specify that _STM should be called before _GTF but nothing seems to mandate use of _GTM and _STM. I think libata-acpi has several issues here. 1. Missing _GTM/_STM support. This is because mode programming is essential to PATA controllers and we do it in more conventional way (poking PCI / controller registers) regardless of ACPI, so this feature is kind of redundant. 2. Doing _GTF on boot. _GTF is supposed to configure the device as the firmware would have configured it during a normal boot, so we shouldn't be doing it during boot. This too is in gray area as if we're doing kexec, we might want to do _GTF during boot. It would be the cleanest if _GTF can be modified by but doesn't depend on _STM. Oh, well, there seem to be enough motherboards out there hit by this. I'll cook something up. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
