diff options
| author | Jonathan Currier <dullfire@yahoo.com> | 2024-11-17 17:48:42 -0600 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2025-04-15 08:32:18 +0200 |
| commit | cf761e3dacc6ad5f65a4886d00da1f9681e6805a (patch) | |
| tree | 7d5607abc6d650517fa15a070d0f2ba6746ae28e /drivers | |
| parent | 8ffd015db85fea3e15a77027fda6c02ced4d2444 (diff) | |
PCI/MSI: Add an option to write MSIX ENTRY_DATA before any reads
Commit 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries") introduced a
readl() from ENTRY_VECTOR_CTRL before the writel() to ENTRY_DATA.
This is correct, however some hardware, like the Sun Neptune chips, the NIU
module, will cause an error and/or fatal trap if any MSIX table entry is
read before the corresponding ENTRY_DATA field is written to.
Add an optional early writel() in msix_prepare_msi_desc().
Fixes: 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries")
Signed-off-by: Jonathan Currier <dullfire@yahoo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241117234843.19236-2-dullfire@yahoo.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/msi/msi.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c index 6569ba3577fe..8b8848788618 100644 --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -615,6 +615,9 @@ void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc) void __iomem *addr = pci_msix_desc_addr(desc); desc->pci.msi_attrib.can_mask = 1; + /* Workaround for SUN NIU insanity, which requires write before read */ + if (dev->dev_flags & PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST) + writel(0, addr + PCI_MSIX_ENTRY_DATA); desc->pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); } } |