On Wed, May 22, 2013 at 7:12 AM, Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> wrote: > In a PCI configuration header, the 'devsel' bits of the status > register are read-only, and indicate the timing of the secondary > interface. Currently, we implement them as read/write, so when the > Linux PCI core writes all 1's to this register, it gets 11b as the > 'devsel' value, which is reserved. I suppose the problem is that pci_scan_bridge() writes 0xffff to the PCI_STATUS register? PCI_STATUS is documented as containing either RO or RW1C (write-1-to-clear status) bits, so it makes sense to write all ones to clear all status bits. But there are other RO bits that I think you should mask out, too: Interrupt Status, Capabilities List, etc. Maybe if you fix this, it will also fix the Capability List issue you saw in patch 3/4. > This commit fixes the PCI-to-PCI bridge emulation of the Marvell PCIe > driver to ensure those bits remain set to 00b, which indicate a fast > devsel decoding. > > This allows to fix the lspci -v output from: > > Flags: bus master, 66MHz, user-definable features, ?? devsel, latency 0 > > to: > > Flags: bus master, 66MHz, user-definable features, fast devsel, latency 0 > > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> > --- > drivers/pci/host/pci-mvebu.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c > index c887598..d730bf4 100644 > --- a/drivers/pci/host/pci-mvebu.c > +++ b/drivers/pci/host/pci-mvebu.c > @@ -490,6 +490,11 @@ static int mvebu_sw_pci_bridge_write(struct mvebu_pcie_port *port, > case PCI_COMMAND: > bridge->command = value & 0xffff; > bridge->status = value >> 16; > + /* > + * The devsel bits are read-only, and we want to keep > + * them set to 0 > + */ > + bridge->status &= ~PCI_STATUS_DEVSEL_MASK; > break; > > case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1: > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
