On Tue, May 8, 2012 at 3:09 AM, Hao, Xudong <xudong.hao@xxxxxxxxx> wrote: >> -----Original Message----- >> From: Bjorn Helgaas [mailto:bhelgaas@xxxxxxxxxx] >> > } >> > >> >> This doesn't make any sense to me. "pos" is the offset of the PCI >> Express Capability (identifier 10h). LTR is a separate extended >> capability (identifier 18h), so you at least have to look up its >> offset. >> > Sorry paste a wrong patch... > > How about this patch, not a formal patch. > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 111569c..eced407 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -910,6 +910,45 @@ static void pci_restore_pcie_state(struct pci_dev *dev) > pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]); > } > > +static int pci_save_ltr_value(struct pci_dev *dev) > +{ > + int i = 0, pos; > + struct pci_cap_saved_state *save_state; > + u16 *cap; > + > + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); > + if (!pos) > + return -ENOTSUPP; > + > + save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR); > + if (!save_state) { > + dev_err(&dev->dev, "buffer not found in %s\n", __func__); > + return -ENOMEM; > + } > + cap = (u16 *)&save_state->cap.ltr_data[0]; > + > + pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, &cap[i++]); > + pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, &cap[i++]); > +} > + > +static void pci_restore_ltr_value(struct pci_dev *dev) > +{ > + int i = 0, pos; > + struct pci_cap_saved_state *save_state; > + u16 *cap; > + > + if (!pci_ltr_supported(dev)) > + return; > + > + save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR); > + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); > + if (!save_state || !pos) > + return; > + cap = (u16 *)&save_state->cap.ltr_data[0]; > + > + pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, cap[i++]); > + pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, cap[i++]); > +} > > static int pci_save_pcix_state(struct pci_dev *dev) > { > @@ -964,6 +1003,10 @@ pci_save_state(struct pci_dev *dev) > return i; > if ((i = pci_save_pcix_state(dev)) != 0) > return i; > + > + if (pci_ltr_supported(dev)) > + return pci_save_ltr_value(dev); > + > return 0; > } > > @@ -1032,6 +1075,7 @@ void pci_restore_state(struct pci_dev *dev) > pci_restore_pcix_state(dev); > pci_restore_msi_state(dev); > pci_restore_iov_state(dev); > + pci_restore_ltr_value(dev); > > dev->state_saved = false; > } > diff --git a/include/linux/pci.h b/include/linux/pci.h > index e444f5b..6343aeb 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -220,6 +220,7 @@ struct pci_cap_saved_data { > char cap_nr; > unsigned int size; > u32 data[0]; > + u32 ltr_data[0]; > }; > > struct pci_cap_saved_state { Did you test this? I can't believe this works at all. You're calling "pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR)", which searches the pci_dev->saved_cap_space list, but you never add a PCI_EXT_CAP_ID_LTR buffer to that list. Bjorn -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
