When a driver enables MSI-X, msix_program_entries() reads the MSI-X Vector
Control register for each vector and saves it in desc->masked. Each
register is 32 bits and bit 0 is the actual Mask bit.
When we restored these registers during resume, we previously set the Mask
bit if *any* bit in desc->masked was set instead of when the Mask bit
itself was set:
pci_restore_state
pci_restore_msi_state
__pci_restore_msix_state
for_each_pci_msi_entry
msix_mask_irq(entry, entry->masked) <-- entire u32 word
__pci_msix_desc_mask_irq(desc, flag)
mask_bits = desc->masked & ~PCI_MSIX_ENTRY_CTRL_MASKBIT
if (flag) <-- testing entire u32, not just bit 0
mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT
writel(mask_bits, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL)
This means that after resume, MSI-X vectors were masked when they shouldn't
be, which leads to timeouts like this:
nvme nvme0: I/O 978 QID 3 timeout, completion polled
On resume, set the Mask bit only when the saved Mask bit from suspend was
set.
This should remove the need for
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| include | ||
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| lib | ||
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| samples | ||
| scripts | ||
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| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.