Re: [PATCH] PCI: Mark INTx masking support of Chelsio T310 10GbE NIC as broken

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-05-25 11:11, Bjorn Helgaas wrote:
> On Fri, May 25, 2012 at 8:02 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote:
>> According to Alexey, the T310 does not properly support INTx masking as
>> it fails to keep the PCI_STATUS_INTERRUPT bit updated once the interrupt
>> is masked. Mark this adapter as broken so that pci_intx_mask_supported
>> won't report it as compatible.
> 
> Please include a reference to a bugzilla, mailing list discussion, or
> other details about how this was found and debugged.  Thanks!

Sorry, it's documented here:
http://thread.gmane.org/gmane.comp.emulators.kvm.devel/91388. Will
repost with this information included once Alexey provided his tested-by.

Jan

> 
>> Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
>> ---
>>
>> Alexey, please test if this catches your case correctly.
>>
>>  drivers/pci/pci.c    |    3 +++
>>  drivers/pci/quirks.c |   12 ++++++++++++
>>  include/linux/pci.h  |    2 ++
>>  3 files changed, 17 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index 8f16900..3a1aeb5 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -2876,6 +2876,9 @@ bool pci_intx_mask_supported(struct pci_dev *dev)
>>        bool mask_supported = false;
>>        u16 orig, new;
>>
>> +       if (dev->broken_intx_masking)
>> +               return false;
>> +
>>        pci_cfg_access_lock(dev);
>>
>>        pci_read_config_word(dev, PCI_COMMAND, &orig);
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index 2a75216..151e174 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -2929,6 +2929,18 @@ static void __devinit disable_igfx_irq(struct pci_dev *dev)
>>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0102, disable_igfx_irq);
>>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x010a, disable_igfx_irq);
>>
>> +/*
>> + * Some devices may pass our check in pci_intx_mask_supported if
>> + * PCI_COMMAND_INTX_DISABLE works though they actually do not properly
>> + * support this feature.
>> + */
>> +static void __devinit quirk_broken_intx_masking(struct pci_dev *dev)
>> +{
>> +       dev->broken_intx_masking = 1;
>> +}
>> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_CHELSIO, 0x0010,
>> +                       quirk_broken_intx_masking);
>> +
>>  static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
>>                          struct pci_fixup *end)
>>  {
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index 17b7b5b..c7cfd73 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -324,6 +324,8 @@ struct pci_dev {
>>        unsigned int    is_hotplug_bridge:1;
>>        unsigned int    __aer_firmware_first_valid:1;
>>        unsigned int    __aer_firmware_first:1;
>> +       unsigned int    broken_intx_masking:1;  /* device's INTx masking
>> +                                                  support is not working */
>>        pci_dev_flags_t dev_flags;
>>        atomic_t        enable_cnt;     /* pci_enable_device has been called */
>>
>> --
>> 1.7.3.4

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