[patch V2 05/19] PCI/MSI: Do not set invalid bits in MSI mask

Thomas Gleixner
2021-07-29T22:34:52Z

msi_mask_irq() takes a mask and a flags argument. The mask argument is used
to mask out bits from the cached mask and the flags argument to set bits.

Some places invoke it with a flags argument which sets bits which are not
used by the device, i.e. when the device supports up to 8 vectors a full
unmask in some places sets the mask to 0xFFFFFF00. While devices probably
do not care, it's still bad practice.

Fixes: 7ba1930db02f ("PCI MSI: Unmask MSI if setup failed")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V2: New patch
---
drivers/pci/msi.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -656,21 +656,21 @@ static int msi_capability_init(struct pc
/* Configure MSI capability structure */
ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
if (ret) {
- msi_mask_irq(entry, mask, ~mask);
+ msi_mask_irq(entry, mask, 0);
free_msi_irqs(dev);
return ret;
}

ret = msi_verify_entries(dev);
if (ret) {
- msi_mask_irq(entry, mask, ~mask);
+ msi_mask_irq(entry, mask, 0);
free_msi_irqs(dev);
return ret;
}

ret = populate_msi_sysfs(dev);
if (ret) {
- msi_mask_irq(entry, mask, ~mask);
+ msi_mask_irq(entry, mask, 0);
free_msi_irqs(dev);
return ret;
}
@@ -962,7 +962,7 @@ static void pci_msi_shutdown(struct pci_
/* Return the device with MSI unmasked as initial states */
mask = msi_mask(desc->msi_attrib.multi_cap);
/* Keep cached state to be restored */
- __pci_msi_desc_mask_irq(desc, mask, ~mask);
+ __pci_msi_desc_mask_irq(desc, mask, 0);

/* Restore dev->irq to its default pin-assertion IRQ */
dev->irq = desc->msi_attrib.default_irq;