Messages in this thread |  | | Date | Fri, 17 Jan 2014 15:01:10 -0700 (MST) | From | Keith Busch <> | Subject | Re: [PATCH v2 5/9] nvme: Fix invalid call to irq_set_affinity_hint() |
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On Fri, 17 Jan 2014, Bjorn Helgaas wrote:
> On Fri, Jan 17, 2014 at 9:02 AM, Alexander Gordeev <agordeev@redhat.com> wrote: >> In case MSI-X and MSI initialization failed the function >> irq_set_affinity_hint() is called with uninitialized value >> in dev->entry[0].vector. This update fixes the issue. > > dev->entry[0].vector is initialized in nvme_dev_map(), and it's used > for free_irq() above the area of your patch, so I don't think this is > actually a bug, though it might be somewhat confusing.
It is confusing, but there's a reason. :)
We send a single command using legacy irq to discover how many msix vectors we want. The legacy entry needs to be set some time before calling request_irq in nvme_configure_admin_queue, but also within nvme_dev_start (for power-management). I don't think there's a place to set it that won't look odd when looking at nvme_setup_io_queues. I settled on 'nvme_dev_map' was because 'nvme_dev_unmap' invalidates the entries, so this seemed to provide some amount of symmetry.
>> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> >> --- >> drivers/block/nvme-core.c | 12 ++++++------ >> 1 files changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c >> index 26d03fa..e292450 100644 >> --- a/drivers/block/nvme-core.c >> +++ b/drivers/block/nvme-core.c >> @@ -1790,15 +1790,15 @@ static int nvme_setup_io_queues(struct nvme_dev *dev) >> vecs = 32; >> for (;;) { >> result = pci_enable_msi_block(pdev, vecs); >> - if (result == 0) { >> - for (i = 0; i < vecs; i++) >> - dev->entry[i].vector = i + pdev->irq; >> - break; >> + if (result > 0) { >> + vecs = result; >> + continue; >> } else if (result < 0) { >> vecs = 1; >> - break; >> } >> - vecs = result; >> + for (i = 0; i < vecs; i++) >> + dev->entry[i].vector = i + pdev->irq; >> + break; >> } >> }
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