|author||Alexander Gordeev <email@example.com>||2013-12-30 08:28:14 +0100|
|committer||Bjorn Helgaas <firstname.lastname@example.org>||2014-01-03 17:17:55 -0700|
PCI/MSI: Remove pci_enable_msi_block_auto()
The new pci_msi_vec_count() interface makes pci_enable_msi_block_auto() superfluous. Drivers can use pci_msi_vec_count() to learn the maximum number of MSIs supported by the device, and then call pci_enable_msi_block(). pci_enable_msi_block_auto() was introduced recently, and its only user is the AHCI driver, which is also updated by this change. Signed-off-by: Alexander Gordeev <email@example.com> Signed-off-by: Bjorn Helgaas <firstname.lastname@example.org> Acked-by: Tejun Heo <email@example.com>
Diffstat (limited to 'Documentation/PCI/MSI-HOWTO.txt')
1 files changed, 6 insertions, 33 deletions
diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt
index a8b41788dfde..aa4ad987510d 100644
@@ -127,49 +127,22 @@ on the number of vectors that can be allocated; pci_enable_msi_block()
returns as soon as it finds any constraint that doesn't allow the
call to succeed.
-int pci_enable_msi_block_auto(struct pci_dev *dev, int *count)
-This variation on pci_enable_msi() call allows a device driver to request
-the maximum possible number of MSIs. The MSI specification only allows
-interrupts to be allocated in powers of two, up to a maximum of 2^5 (32).
-If this function returns a positive number, it indicates that it has
-succeeded and the returned value is the number of allocated interrupts. In
-this case, the function enables MSI on this device and updates dev->irq to
-be the lowest of the new interrupts assigned to it. The other interrupts
-assigned to the device are in the range dev->irq to dev->irq + returned
-value - 1.
-If this function returns a negative number, it indicates an error and
-the driver should not attempt to request any more MSI interrupts for
-If the device driver needs to know the number of interrupts the device
-supports it can pass the pointer count where that number is stored. The
-device driver must decide what action to take if pci_enable_msi_block_auto()
-succeeds, but returns a value less than the number of interrupts supported.
-If the device driver does not need to know the number of interrupts
-supported, it can set the pointer count to NULL.
void pci_disable_msi(struct pci_dev *dev)
This function should be used to undo the effect of pci_enable_msi() or
-pci_enable_msi_block() or pci_enable_msi_block_auto(). Calling it restores
-dev->irq to the pin-based interrupt number and frees the previously
-allocated message signaled interrupt(s). The interrupt may subsequently be
-assigned to another device, so drivers should not cache the value of
+pci_enable_msi_block(). Calling it restores dev->irq to the pin-based
+interrupt number and frees the previously allocated message signaled
+interrupt(s). The interrupt may subsequently be assigned to another
+device, so drivers should not cache the value of dev->irq.
Before calling this function, a device driver must always call free_irq()
on any interrupt for which it previously called request_irq().
Failure to do so results in a BUG_ON(), leaving the device with
MSI enabled and thus leaking its vector.
int pci_msi_vec_count(struct pci_dev *dev)