diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2008-12-23 04:08:29 +0100 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-01-07 20:13:23 +0100 |
| commit | 6a479079c07211bf348ac8a79754f26bea258f26 (patch) | |
| tree | 1587c0ed9446c7d0d6ab8a38d1524132e2faae35 /drivers/pci/pci.c | |
| parent | PCI hotplug: remove redundant test in cpq hotplug (diff) | |
| download | linux-6a479079c07211bf348ac8a79754f26bea258f26.tar.xz linux-6a479079c07211bf348ac8a79754f26bea258f26.zip | |
PCI: Add pci_clear_master() as opposite of pci_set_master()
During an online device reset it may be useful to disable bus-mastering.
pci_disable_device() does that, and far more besides, so is not suitable
for an online reset.
Add pci_clear_master() which does just this.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c824dc8d617c..f3fd55df67db 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1667,6 +1667,22 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name) ((1 << 6) - 1), res_name); } +static void __pci_set_master(struct pci_dev *dev, bool enable) +{ + u16 old_cmd, cmd; + + pci_read_config_word(dev, PCI_COMMAND, &old_cmd); + if (enable) + cmd = old_cmd | PCI_COMMAND_MASTER; + else + cmd = old_cmd & ~PCI_COMMAND_MASTER; + if (cmd != old_cmd) { + dev_dbg(&dev->dev, "%s bus mastering\n", + enable ? "enabling" : "disabling"); + pci_write_config_word(dev, PCI_COMMAND, cmd); + } + dev->is_busmaster = enable; +} /** * pci_set_master - enables bus-mastering for device dev @@ -1675,21 +1691,21 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name) * Enables bus-mastering on the device and calls pcibios_set_master() * to do the needed arch specific settings. */ -void -pci_set_master(struct pci_dev *dev) +void pci_set_master(struct pci_dev *dev) { - u16 cmd; - - pci_read_config_word(dev, PCI_COMMAND, &cmd); - if (! (cmd & PCI_COMMAND_MASTER)) { - dev_dbg(&dev->dev, "enabling bus mastering\n"); - cmd |= PCI_COMMAND_MASTER; - pci_write_config_word(dev, PCI_COMMAND, cmd); - } - dev->is_busmaster = 1; + __pci_set_master(dev, true); pcibios_set_master(dev); } +/** + * pci_clear_master - disables bus-mastering for device dev + * @dev: the PCI device to disable + */ +void pci_clear_master(struct pci_dev *dev) +{ + __pci_set_master(dev, false); +} + #ifdef PCI_DISABLE_MWI int pci_set_mwi(struct pci_dev *dev) { @@ -2346,6 +2362,7 @@ EXPORT_SYMBOL(pci_release_selected_regions); EXPORT_SYMBOL(pci_request_selected_regions); EXPORT_SYMBOL(pci_request_selected_regions_exclusive); EXPORT_SYMBOL(pci_set_master); +EXPORT_SYMBOL(pci_clear_master); EXPORT_SYMBOL(pci_set_mwi); EXPORT_SYMBOL(pci_try_set_mwi); EXPORT_SYMBOL(pci_clear_mwi); |