diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2007-03-05 11:30:07 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-05 18:57:50 +0300 |
| commit | f5f2b13129a6541debf8851bae843cbbf48298b7 (patch) | |
| tree | 274dc998519074e56259a7dc4bd611652b8d930e /drivers/pci/pci.c | |
| parent | 58a53b246b4aed95f3f93b45828c8d9f26b1cfcb (diff) | |
| download | linux-f5f2b13129a6541debf8851bae843cbbf48298b7.tar.xz | |
[PATCH] msi: sanely support hardware level msi disabling
In some cases when we are not using msi we need a way to ensure that the
hardware does not have an msi capability enabled. Currently the code has been
calling disable_msi_mode to try and achieve that. However disable_msi_mode
has several other side effects and is only available when msi support is
compiled in so it isn't really appropriate.
Instead this patch implements pci_msi_off which disables all msi and msix
capabilities unconditionally with no additional side effects.
pci_disable_device was redundantly clearing the bus master enable flag and
clearing the msi enable bit. A device that is not allowed to perform bus
mastering operations cannot generate intx or msi interrupt messages as those
are essentially a special case of dma, and require bus mastering. So the call
in pci_disable_device to disable msi capabilities was redundant.
quirk_pcie_pxh also called disable_msi_mode and is updated to use pci_msi_off.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1e74e1ee8bd8..df495300ce3d 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -881,13 +881,6 @@ pci_disable_device(struct pci_dev *dev) if (atomic_sub_return(1, &dev->enable_cnt) != 0) return; - if (dev->msi_enabled) - disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI), - PCI_CAP_ID_MSI); - if (dev->msix_enabled) - disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI), - PCI_CAP_ID_MSIX); - pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; @@ -1277,6 +1270,33 @@ pci_intx(struct pci_dev *pdev, int enable) } } +/** + * pci_msi_off - disables any msi or msix capabilities + * @pdev: the PCI device to operate on + * + * If you want to use msi see pci_enable_msi and friends. + * This is a lower level primitive that allows us to disable + * msi operation at the device level. + */ +void pci_msi_off(struct pci_dev *dev) +{ + int pos; + u16 control; + + pos = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (pos) { + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); + control &= ~PCI_MSI_FLAGS_ENABLE; + pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); + } + pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); + if (pos) { + pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control); + control &= ~PCI_MSIX_FLAGS_ENABLE; + pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control); + } +} + #ifndef HAVE_ARCH_PCI_SET_DMA_MASK /* * These can be overridden by arch-specific implementations |