diff options
| author | Matthew Wilcox <willy@debian.org> | 2003-07-03 01:50:39 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <greg@kroah.com> | 2003-07-03 01:50:39 -0700 |
| commit | 5b34c381fc70278c6c2d141e38fbd44fec55f04b (patch) | |
| tree | a046347f69fd698f382c0f8a61ce9b21b0c7d785 /Documentation | |
| parent | 81fce257d30bd969d01ed45a4cca73725f6aba8c (diff) | |
[PATCH] PCI: Improve documentation
Fix some grammar problems
Add a note about Fast Back to Back support
Change the slot_name recommendation to pci_name().
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/pci.txt | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/Documentation/pci.txt b/Documentation/pci.txt index 15c52173d047..d30dc107ac62 100644 --- a/Documentation/pci.txt +++ b/Documentation/pci.txt @@ -7,14 +7,14 @@ The world of PCI is vast and it's full of (mostly unpleasant) surprises. Different PCI devices have different requirements and different bugs -- because of this, the PCI support layer in Linux kernel is not as trivial as one would wish. This short pamphlet tries to help all potential driver -authors to find their way through the deep forests of PCI handling. +authors find their way through the deep forests of PCI handling. 0. Structure of PCI drivers ~~~~~~~~~~~~~~~~~~~~~~~~~~~ There exist two kinds of PCI drivers: new-style ones (which leave most of probing for devices to the PCI layer and support online insertion and removal -of devices [thus supporting PCI, hot-pluggable PCI and CardBus in single +of devices [thus supporting PCI, hot-pluggable PCI and CardBus in a single driver]) and old-style ones which just do all the probing themselves. Unless you have a very good reason to do so, please don't use the old way of probing in any new code. After the driver finds the devices it wishes to operate @@ -174,7 +174,7 @@ which enables the bus master bit in PCI_COMMAND register and also fixes the latency timer value if it's set to something bogus by the BIOS. If you want to use the PCI Memory-Write-Invalidate transaction, -call pci_set_mwi(). This enables bit PCI_COMMAND bit for Mem-Wr-Inval +call pci_set_mwi(). This enables the PCI_COMMAND bit for Mem-Wr-Inval and also ensures that the cache line size register is set correctly. Make sure to check the return value of pci_set_mwi(), not all architectures may support Memory-Write-Invalidate. @@ -236,7 +236,7 @@ pci_clear_mwi() Disable Memory-Write-Invalidate transactions. 7. Miscellaneous hints ~~~~~~~~~~~~~~~~~~~~~~ When displaying PCI slot names to the user (for example when a driver wants -to tell the user what card has it found), please use pci_dev->slot_name +to tell the user what card has it found), please use pci_name(pci_dev) for this purpose. Always refer to the PCI devices by a pointer to the pci_dev structure. @@ -248,6 +248,10 @@ can be pretty complex. If you're going to use PCI bus mastering DMA, take a look at Documentation/DMA-mapping.txt. +Don't try to turn on Fast Back to Back writes in your driver. All devices +on the bus need to be capable of doing it, so this is something which needs +to be handled by platform and generic code, not individual drivers. + 8. Obsolete functions ~~~~~~~~~~~~~~~~~~~~~ |
