On Tue, Nov 6, 2012 at 3:04 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > The ROM address handling in gdth_init_pci() is useless and possibly > dangerous. This patch removes it. > > "pci_resource_start(pdev, 8)" is not well-defined. PCI resources 0-5 are > standard PCI BARs and 6 is the expansion ROM. Resource 8 is either an > SR-IOV BAR (if CONFIG_PCI_IOV=y, resources 7-12 are SR-IOV BARs) or a > bridge window (resources 7-10). > > The GDT device is neither an SR-IOV device nor a bridge, so in either case > resource 8 should be zero since struct pci_dev is allocated with kzalloc(). > > It is illegal for a driver to write an arbitrary address to the ROM BAR > because it has no way of knowing whether the ROM will conflict with another > device. > > I think the only effect of the code being removed was to: > > 1) Enable the ROM at 0xFEFF0000 (possibly causing a conflict with > another device) > 2) Delay one millisecond > 3) Write zero to the ROM BAR, disabling it > > I doubt the delay is needed, but I left it since it seems innocuous. > > Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > --- > drivers/scsi/gdth.c | 10 ++-------- > 1 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c > index 5d72274..3efe4ef 100644 > --- a/drivers/scsi/gdth.c > +++ b/drivers/scsi/gdth.c > @@ -1107,14 +1107,8 @@ static int __devinit gdth_init_pci(struct pci_dev *pdev, gdth_pci_str *pcistr, > pci_read_config_word(pdev, PCI_COMMAND, &command); > command |= 6; > pci_write_config_word(pdev, PCI_COMMAND, command); > - if (pci_resource_start(pdev, 8) == 1UL) > - pci_resource_start(pdev, 8) = 0UL; > - i = 0xFEFF0001UL; > - pci_write_config_dword(pdev, PCI_ROM_ADDRESS, i); > - gdth_delay(1); > - pci_write_config_dword(pdev, PCI_ROM_ADDRESS, > - pci_resource_start(pdev, 8)); > - > + gdth_delay(1); > + > dp6m_ptr = ha->brd; > > /* Ensure that it is safe to access the non HW portions of DPMEM. > Ping? -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
