Messages in this thread Patch in this message | | | Date | Mon, 26 Apr 2010 16:44:16 +0200 | From | Stefan Richter <> | Subject | Re: [PATCH 2/2] firewire: ohci: add MSI support |
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(adding Cc: lkml, quoting in full)
Clemens Ladisch wrote: > This patch adds support for message-signaled interrupts. > > Any native PCI-Express OHCI controller should support MSI, but most are > just PCI cores behind a PCI-E/PCI bridge. The only chips that are known > to claim to support MSI are the Lucent/Agere/LSI FW643 and the VIA > VT6315, none of which I have been able to test.
I got a FW643 card a few days ago and can test that one. Also, I have a JMicron JMB381 native PCIe 1394a controller. The latter is a less ideal test specimen since it is buggy already without MSI (soon stops to operate if one dares to mix isochronous and asynchronous I/O; sometimes also if there is a bus reset at an inconvenient time).
From lspci:
04:00.0 FireWire (IEEE 1394): Agere Systems FW643 PCI Express1394b Controller (PHY/Link) (rev 07) (prog-if 10 [OHCI])
[...] Capabilities: [4c] MSI: Enable- Count=1/1 Maskable- 64bit+
Address: 0000000000000000 Data: 0000
Capabilities: [60] Express (v1) Endpoint, MSI 00
[...]
0a:00.0 FireWire (IEEE 1394): JMicron Technology Corp. IEEE 1394 Host Controller (prog-if 10 [OHCI])
[...] Capabilities: [80] Express (v1) Endpoint, MSI 00
[...] Capabilities: [94] MSI: Enable- Count=1/1 Maskable- 64bit-
Address: fffffffc Data: 0000
[...]
Does "MSI 00", "MSI: Enable-" mean they do or don't support MSI? Asks a PCIe newbie.
The FW643 (actually two of them) sits behind a PCIe switch:
03:04.0 PCI bridge: PLX Technology, Inc. PEX 8505 5-lane, 5-port PCI Express Switch (rev aa) (prog-if 00 [Normal decode])
[...] Capabilities: [48] MSI: Enable+ Count=1/2 Maskable+ 64bit+
Address: 00000000fee0f00c Data: 41a1
Masking: 00000003 Pending: 00000000
Capabilities: [68] Express (v1) Downstream Port (Slot+), MSI 00
[...]
I hope this switch does not make things any more interesting.
> Due to the high level of trust I have in the competence of these and any > future chip makers, I thought it a good idea to add a disable-MSI quirk. > > Signed-off-by: Clemens Ladisch <clemens@ladisch.de> > --- > drivers/firewire/ohci.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > --- a/drivers/firewire/ohci.c > +++ b/drivers/firewire/ohci.c > @@ -237,6 +237,7 @@ static char ohci_driver_name[] = KBUILD_ > #define QUIRK_RESET_PACKET 2 > #define QUIRK_BE_HEADERS 4 > #define QUIRK_NO_1394A 8 > +#define QUIRK_NO_MSI 16 > > /* In case of multiple matches in ohci_quirks[], only the first one is used. */ > static const struct { > @@ -260,6 +261,7 @@ MODULE_PARM_DESC(quirks, "Chip quirks (d > ", reset packet generation = " __stringify(QUIRK_RESET_PACKET) > ", AR/selfID endianess = " __stringify(QUIRK_BE_HEADERS) > ", no 1394a enhancements = " __stringify(QUIRK_NO_1394A) > + ", disable MSI = " __stringify(QUIRK_NO_MSI) > ")"); > > #define OHCI_PARAM_DEBUG_AT_AR 1 > @@ -1718,10 +1720,13 @@ static int ohci_enable(struct fw_card *c > > reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000); > > + if (!(ohci->quirks & QUIRK_NO_MSI)) > + pci_enable_msi(dev); > if (request_irq(dev->irq, irq_handler, > - IRQF_SHARED, ohci_driver_name, ohci)) { > + pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED, > + ohci_driver_name, ohci)) { > - fw_error("Failed to allocate shared interrupt %d.\n", > - dev->irq); > + fw_error("Failed to allocate interrupt %d.\n", dev->irq); > + pci_disable_msi(dev); > dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, > ohci->config_rom, ohci->config_rom_bus); > return -EIO; > @@ -2625,6 +2630,7 @@ static void pci_remove(struct pci_dev *d > context_release(&ohci->at_response_ctx); > kfree(ohci->it_context_list); > kfree(ohci->ir_context_list); > + pci_disable_msi(dev); > pci_iounmap(dev, ohci->registers); > pci_release_region(dev, 0); > pci_disable_device(dev); > @@ -2642,6 +2648,7 @@ static int pci_suspend(struct pci_dev *d > > software_reset(ohci); > free_irq(dev->irq, ohci); > + pci_disable_msi(dev); > err = pci_save_state(dev); > if (err) { > fw_error("pci_save_state failed\n");
Looks right, but what do I know? -- Stefan Richter -=====-==-=- -=-- ==-=- http://arcgraph.de/sr/
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