lkml.org 
[lkml]   [2009]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] Fix MSI-X with NIU cards
    From
    Date
    On Wed, 2009-05-13 at 13:40 +0900, Hidetoshi Seto wrote:
    > Hidetoshi Seto wrote:
    > > It seems that this issue was introduced by Matthew's commit:
    > > commit f2440d9acbe866b917b16cc0f927366341ce9215
    > > <quote>
    > > @@ -435,11 +432,12 @@ static int msix_capability_init(struct pci_dev *dev,
    > > entry->msi_attrib.is_msix = 1;
    > > entry->msi_attrib.is_64 = 1;
    > > entry->msi_attrib.entry_nr = j;
    > > - entry->msi_attrib.maskbit = 1;
    > > - entry->msi_attrib.masked = 1;
    > > entry->msi_attrib.default_irq = dev->irq;
    > > entry->msi_attrib.pos = pos;
    > > entry->mask_base = base;
    > > + entry->masked = readl(base + j * PCI_MSIX_ENTRY_SIZE +
    > > + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
    > > + msix_mask_irq(entry, 1);
    > >
    > > list_add_tail(&entry->list, &dev->msi_list);
    > > }
    > > </quote>
    > >
    > > I'm not sure why Matthew changed it to read/write...
    >
    > Sorry, I got it.
    >
    > The problem is not the bit[0] for mask, but the reserved bits[31::01].
    > According to the Spec:
    > "31::01 Reserved
    > After reset, the state of these bits must be 0.
    > However, for potential future use, software must preserve the value of
    > these reserved bits when modifying the value of other Vector Control bits.
    > If software modifies the value of these reserved bits, the result is
    > undefined."

    Yes that's what I was referring to about it being out of spec.

    So to work around the NIU bug and be in spec I think we need to enable
    MSI, then read the mask bits, then write them back with the mask bit
    set.

    cheers

    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2009-05-13 06:51    [W:3.293 / U:0.316 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site