Messages in this thread | | | Date | Sat, 09 Jun 2007 12:48:47 -0700 | From | "Kok, Auke" <> | Subject | Re: [PATCH 1/2] [RFC] PCI: read revision ID by default |
| |
Grant Grundler wrote: > On Fri, Jun 08, 2007 at 03:46:30PM -0700, Auke Kok wrote: >> Currently there are 97 occurrences where drivers need the pci >> revision ID. We can do this once for all devices. Even the pci >> subsystem needs the revision several times for quirks. The extra >> u8 member pads out nicely in the pci_dev struct. > > Good idea. I always wondered why we read the invariants so often > in the code. > >> Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com> >> --- >> >> drivers/pci/probe.c | 3 +++ >> include/linux/pci.h | 1 + >> 2 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >> index e48fcf0..0fdb71d 100644 >> --- a/drivers/pci/probe.c >> +++ b/drivers/pci/probe.c >> @@ -918,6 +918,9 @@ pci_scan_device(struct pci_bus *bus, int devfn) >> dev->cfg_size = pci_cfg_space_size(dev); >> dev->error_state = pci_channel_io_normal; >> >> + /* read the PCI revision: 1 byte */ >> + pci_read_config_byte(dev, PCI_REVISION_ID, &dev->revision); > > probe.c:pci_setup_device() is also reading this byte but discards it: > pci_read_config_dword(dev, PCI_CLASS_REVISION, &class); > class >>= 8; /* upper 3 bytes */ > dev->class = class; > > Can you use "class & 0xff"? Or is pci_setup_device() too late? > Or can you read the whole 32-bits in pci_scan_device() and remove > the pci_read_config() in pci_setup_device()?
no, pci_setup_device() is just called right after the location where I read the REVISION_ID. I'll remove the read and put the dev->revision right after where we read the class dword.
Auke - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |