Re: pata_jmicron triggers warning in PCIe code

[Robert Hancock <hancockrwd@gmail.com>]

On 11/23/2011 08:43 AM, Josh Boyer wrote:
> Hi,
>
> We have a report of the pata_jmicron driver hitting the following
> warning in the 3.1.x kernel series:
>
> WARNING: at drivers/pci/search.c:44 pci_find_upstream_pcie_bridge+0x56/0x6f()
> Hardware name: System Product Name
> Modules linked in: pata_jmicron(+)
> Pid: 256, comm: modprobe Not tainted 3.1.1-1.fc16.x86_64 #1
> Call Trace:
>   [<ffffffff81057a1e>] warn_slowpath_common+0x83/0x9b
>   [<ffffffff81057a50>] warn_slowpath_null+0x1a/0x1c
>   [<ffffffff81241643>] pci_find_upstream_pcie_bridge+0x56/0x6f
>   [<ffffffff814b45d4>] get_domain_for_dev.part.9.constprop.13+0x2e/0x47f
>   [<ffffffff814b4bf9>] __get_valid_domain_for_dev+0x2c/0xa0
>   [<ffffffff813c1ca3>] __intel_map_single+0x5a/0x172
>   [<ffffffff811103e8>] ? alloc_pages_current+0xc7/0xd8
>   [<ffffffff813c1eb7>] intel_alloc_coherent+0xc7/0xee
>   [<ffffffff812e7612>] ? dmam_noncoherent_release+0x1b/0x1b
>   [<ffffffff812e757c>] dma_alloc_coherent+0x80/0x82
>   [<ffffffff812e7721>] dmam_alloc_coherent+0x58/0x9c
>   [<ffffffff81317e88>] ata_bmdma_port_start+0x43/0x58
>   [<ffffffff81309ef6>] ata_host_start+0xdd/0x168
>   [<ffffffff813184fd>] ? __ata_sff_interrupt+0x179/0x179
>   [<ffffffff81318709>] ata_pci_sff_activate_host+0x36/0x1e0
>   [<ffffffff813c2b1f>] ? pcibios_set_master+0x88/0x8f
>   [<ffffffff81318bc7>] ata_pci_bmdma_init_one+0xc2/0xf8
>   [<ffffffffa0000032>] jmicron_init_one+0x32/0x34 [pata_jmicron]
>   [<ffffffff8123fce7>] local_pci_probe+0x44/0x75
>   [<ffffffff8124084a>] pci_device_probe+0xd0/0xff
>   [<ffffffff812dea17>] driver_probe_device+0x131/0x213
>   [<ffffffff812deb53>] __driver_attach+0x5a/0x7e
>   [<ffffffff812deaf9>] ? driver_probe_device+0x213/0x213
>   [<ffffffff812dda9f>] bus_for_each_dev+0x53/0x89
>   [<ffffffff812de5f6>] driver_attach+0x1e/0x20
>   [<ffffffff812de21a>] bus_add_driver+0xd1/0x224
>   [<ffffffffa0002000>] ? 0xffffffffa0001fff
>   [<ffffffff812deff7>] driver_register+0x98/0x105
>   [<ffffffffa0002000>] ? 0xffffffffa0001fff
>   [<ffffffff8124110d>] __pci_register_driver+0x56/0xc1
>   [<ffffffffa0002000>] ? 0xffffffffa0001fff
>   [<ffffffffa000201e>] jmicron_init+0x1e/0x20 [pata_jmicron]
>   [<ffffffff81002099>] do_one_initcall+0x7f/0x136
>   [<ffffffff8108a595>] sys_init_module+0x88/0x1d0
>   [<ffffffff814bd8c2>] system_call_fastpath+0x16/0x1b
>
> That boils down to the following check:
>
>                  /* PCI device should connect to a PCIe bridge */
>                  if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) {
>                          /* Busted hardware? */
>                          WARN_ON_ONCE(1);
>                          return NULL;
>                  }
>
> I don't recall seeing reports of this on the 3.0 kernel.  Should we add
> some debugging code to print out what pdev->pcie_type is set to here?
> Without knowing that, I can't tell if it's actually finding something weird
> about the hardware, or memory corruption that seems to hit here.
>
> The user has hit it about 3 times thus far, so they can at least recreate
> it fairly easily.
>
> Any other ideas?

Well, I don't think it has anything to do with the driver. It seems like 
the code is trying to go from the PCI device up the chain of PCI bridges 
until it finds a PCI-E device that's a bridge. The warning indicates 
that the first PCI-E device it found didn't seem to be a bridge.

Can we get the output of "lspci -vv" on this machine?