My advance apologies if this email gets badly MIME-mangled... On 2010/01/06 20:59, "Robert Hancock" <hancockrwd@xxxxxxxxx> wrote: > On 01/06/2010 03:37 AM, Torsten Kaiser wrote: >> After activating the MSI support by adding sata_sil24.msi=1 to the >> kernel command line, the first write to a drive attached to the SiI >> 3132 controller results in the following errors: >> >> [ 138.950074] ata2.00: exception Emask 0x0 SAct 0xf SErr 0x0 action 0x6 >> frozen >> [ 138.961023] ata2.00: failed command: WRITE FPDMA QUEUED >> [ 138.970034] ata2.00: cmd 61/00:00:a5:95:4a/04:00:01:00:00/40 tag 0 >> ncq 524288 out >> [ 138.970037] res 40/00:00:00:00:00/00:00:00:00:00/00 Emask >> 0x4 (timeout) > > Looking at the code in sata_sil24 and the SiI3132 datasheet, there's a > control bit which doesn't seem to be handled in the driver, global > control register bit 30: "MSI Acknowledge (W). Writing a one to this bit > acknowledges a Message Signaled Interrupt and permits generation of > another MSI. This bit is cleared immediately after the acknowledgement > is recognized by the control logic, hence the bit will always be read as > a zero. If all interrupt conditions are removed subsequent to an MSI, it > is not necessary to assert this Acknowledge; another MSI will be > generated when an interrupt condition occurs." > > The way the interrupt handler for this driver works is that we check the > global IRQ status register, and then based on what ports indicated an > interrupt in that register, we check the individual port command > completion registers. The issue would seem to be that if a port got an > interrupt condition in between these two operations, we'd miss it, and > the MSI logic described above then wouldn't generate any more interrupts > since we didn't remove all interrupt conditions. > > Can you try this patch and see if it helps? (Might be whitespace damaged > but hopefully you can apply manually in that case.) I've got this custom board that uses the sata_sil24 driver (off a P2020 processor). My current kernel is a slightly patched 2.6.32 kernel (including the sata_sil24 enable-MSI patch). Unfortunately when I turn MSI on, I get the exact same hang described here, boot log included as dmesg1.txt. With this patch applied, it seems to get a little further (dmesg2.txt), but still dies miserably. I'm relatively sure that MSI works on this chipset as I also have an e1000e controller off an adjacent PCI-E bus which works correctly with MSI. It's relatively critical for me to get MSI working, because the legacy-PCI INTx interrupt for that PCI-E port happens to share an IRQ line with a device that is very unfriendly to shared IRQs (it has no internal IRQ disable register). I'd rather not have to go in there with a soldering iron and some scraps of wire to make it work. :-D Cheers, Kyle Moffett
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dmesg1.txt
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