On Sun, 2008-12-21 at 01:13 +0400, Manu Abraham wrote: > Grant Grundler wrote: > > On Sun, Dec 14, 2008 at 03:15:15PM +0400, Manu Abraham wrote: > > ... > >>> A "GSI" (Generic Sys Interrupt?) is associated with each entry in > >>> the MSI-X table. Driver then calls request_irq() to bind an interrupt > >>> handler to each GSI. So the driver never directly sees the "message". > >> Oh, you mean the array of irq_handlers in the MSI-X table should > >> correspond to a particular message ? > > > > No. I mean each MSI-X entry has an address+message pair and each MSI-X entry > > is associated with the parameters passed to each call of request_irq(). > > Pass in unique private data to each call of request_irq() and the driver > > can determine which message was delivered when the ISR gets called. > > (ISR == Interrupt Service Routine, aka driver IRQ handler) > > > Is it possible that even when the config space says that multiple messages > are supported, you cannot enable MSI-X ? Yes, absolutely. Have a look at pci_msi_check_device() for starters. MSI can be disabled globally, or per-device by a quirk, the bridges above your device might not support MSI and the arch code may prevent MSI/MSI-X for some reason (ie. platform doesn't support it). There's also a check in pci_enable_msix() to make sure the entries you pass in are valid. > ------------- with MSI-X ------------- > > saa716x_pci_init (0): found a NEMO reference board PCIe card > ACPI: PCI Interrupt 0000:05:00.0[A] -> GSI 19 (level, low) -> IRQ 19 > PCI: Setting latency timer of device 0000:05:00.0 to 64 > saa716x_request_irq (0): Using MSI-X mode > saa716x_enable_msix (0): MSI-X request failed For starters you should print the error code returned by pci_enable_msix() - unfortunately it returns EINVAL for many different reasons, but it will narrow it down a bit. cheers -- Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person
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