| Message ID | 773b6a8a-00ac-a275-c80b-d5909ca58f19@gmail.com |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI/ASPM: add sysfs attribute for controlling ASPM | expand |
Evening, Heiner Kallweit wrote on 5/11/19 10:33 AM:> +static ssize_t aspm_disable_link_state_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + struct pcie_link_state *link; > + int len = 0, i; > + > + link = aspm_get_parent_link(pdev); > + if (!link) > + return -EOPNOTSUPP; > + > + mutex_lock(&aspm_lock); > + > + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { > + const struct aspm_sysfs_state *st = aspm_sysfs_states + i; > + > + if (link->aspm_disable & st->disable_mask) > + len += scnprintf(buf + len, PAGE_SIZE - len, "[%s] ", > + st->name); > + else > + len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", > + st->name); > + } > + > + if (link->clkpm_disable) > + len += scnprintf(buf + len, PAGE_SIZE - len, "[CLKPM] "); > + else > + len += scnprintf(buf + len, PAGE_SIZE - len, "CLKPM "); > + > + mutex_unlock(&aspm_lock); > + > + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); > + > + return len; > +} I think it would be better to model the output to something similar to what lspci would do: L1.1- L1.2- L0S+ ClockPM+, etc... This better conveys the message that these states are enabled vs disabled. I'd be interested to know if the use of [STATE]/STATE pattern is used elsewhere in the kernel. If so, then I'm cool with it :) > + > +static ssize_t aspm_disable_link_state_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t len) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + struct pcie_link_state *link; > + char *buftmp = (char *)buf, *tok; > + unsigned int disable_aspm, disable_clkpm; > + bool first = true, add; > + int err = 0, i; > + > + if (aspm_disabled) > + return -EPERM; > + > + link = aspm_get_parent_link(pdev); > + if (!link) > + return -EOPNOTSUPP; > + > + down_read(&pci_bus_sem); > + mutex_lock(&aspm_lock); > + > + disable_aspm = link->aspm_disable; > + disable_clkpm = link->clkpm_disable; > + > + while ((tok = strsep(&buftmp, " \n")) != NULL) { > + bool found = false; > + > + if (!*tok) > + continue; > + > + if (first) { > + if (!strcasecmp(tok, "none")) { > + disable_aspm = 0; > + disable_clkpm = 0; > + break; > + } > + if (!strcasecmp(tok, "all")) { > + disable_aspm = ASPM_STATE_ALL; > + disable_clkpm = 1; > + break; > + } > + first = false; > + } > + > + if (*tok != '+' && *tok != '-') { > + err = -EINVAL; > + goto out; > + } > + > + add = *tok++ == '+'; > + > + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { > + const struct aspm_sysfs_state *st = > + aspm_sysfs_states + i; > + > + if (!strcasecmp(tok, st->name)) { > + if (add) > + disable_aspm |= st->disable_mask; > + else > + disable_aspm &= ~st->disable_mask; > + found = true; > + break; > + } > + } > + > + if (!found && !strcasecmp(tok, "clkpm")) { > + disable_clkpm = add ? 1 : 0; > + found = true; > + } > + > + if (!found) { > + err = -EINVAL; > + goto out; > + } > + } > + > + if (disable_aspm & ASPM_STATE_L1) > + disable_aspm |= ASPM_STATE_L1SS; > + > + link->aspm_disable = disable_aspm; > + link->clkpm_disable = disable_clkpm; > + > + pcie_config_aspm_link(link, policy_to_aspm_state(link)); > + pcie_set_clkpm(link, policy_to_clkpm_state(link)); > +out: > + mutex_unlock(&aspm_lock); > + up_read(&pci_bus_sem); > + > + return err ?: len; > +} > + > +static DEVICE_ATTR_RW(aspm_disable_link_state); > Since we're introducing a new sysfs interface, would it be more appropriate to rename the sysfs files to aspm_set_link_state (or something to that effect)? The syntax as it stands, means that to enable a state, a double negative must be used: echo "-L1.1" > ./aspm_disable_link_state" vs echo "+L1.1" > ./aspm_set_link_state If we avoid the double negative, the documentation about to be written will be more clear and use of the sysfs file will be more intuitive. Thanks, Frederick Lawler
On 12.05.2019 03:02, Frederick Lawler wrote: > Evening, > > Heiner Kallweit wrote on 5/11/19 10:33 AM:> +static ssize_t aspm_disable_link_state_show(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + struct pcie_link_state *link; >> + int len = 0, i; >> + >> + link = aspm_get_parent_link(pdev); >> + if (!link) >> + return -EOPNOTSUPP; >> + >> + mutex_lock(&aspm_lock); >> + >> + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { >> + const struct aspm_sysfs_state *st = aspm_sysfs_states + i; >> + >> + if (link->aspm_disable & st->disable_mask) >> + len += scnprintf(buf + len, PAGE_SIZE - len, "[%s] ", >> + st->name); >> + else >> + len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", >> + st->name); >> + } >> + >> + if (link->clkpm_disable) >> + len += scnprintf(buf + len, PAGE_SIZE - len, "[CLKPM] "); >> + else >> + len += scnprintf(buf + len, PAGE_SIZE - len, "CLKPM "); >> + >> + mutex_unlock(&aspm_lock); >> + >> + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); >> + >> + return len; >> +} > > I think it would be better to model the output to something similar to what lspci would do: > > L1.1- L1.2- L0S+ ClockPM+, etc... > > This better conveys the message that these states are enabled vs disabled. > > I'd be interested to know if the use of [STATE]/STATE pattern is used elsewhere in the kernel. If so, then I'm cool with it :) > This pattern is used in several places in sysfs. At first for "1 of n" selections like in /sys/module/pcie_aspm/parameters/policy. But also for "m of n" selections, examples would be LED triggers or active remote control protocols (drivers/media/rc). >> + >> +static ssize_t aspm_disable_link_state_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t len) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + struct pcie_link_state *link; >> + char *buftmp = (char *)buf, *tok; >> + unsigned int disable_aspm, disable_clkpm; >> + bool first = true, add; >> + int err = 0, i; >> + >> + if (aspm_disabled) >> + return -EPERM; >> + >> + link = aspm_get_parent_link(pdev); >> + if (!link) >> + return -EOPNOTSUPP; >> + >> + down_read(&pci_bus_sem); >> + mutex_lock(&aspm_lock); >> + >> + disable_aspm = link->aspm_disable; >> + disable_clkpm = link->clkpm_disable; >> + >> + while ((tok = strsep(&buftmp, " \n")) != NULL) { >> + bool found = false; >> + >> + if (!*tok) >> + continue; >> + >> + if (first) { >> + if (!strcasecmp(tok, "none")) { >> + disable_aspm = 0; >> + disable_clkpm = 0; >> + break; >> + } >> + if (!strcasecmp(tok, "all")) { >> + disable_aspm = ASPM_STATE_ALL; >> + disable_clkpm = 1; >> + break; >> + } >> + first = false; >> + } >> + >> + if (*tok != '+' && *tok != '-') { >> + err = -EINVAL; >> + goto out; >> + } >> + >> + add = *tok++ == '+'; >> + >> + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { >> + const struct aspm_sysfs_state *st = >> + aspm_sysfs_states + i; >> + >> + if (!strcasecmp(tok, st->name)) { >> + if (add) >> + disable_aspm |= st->disable_mask; >> + else >> + disable_aspm &= ~st->disable_mask; >> + found = true; >> + break; >> + } >> + } >> + >> + if (!found && !strcasecmp(tok, "clkpm")) { >> + disable_clkpm = add ? 1 : 0; >> + found = true; >> + } >> + >> + if (!found) { >> + err = -EINVAL; >> + goto out; >> + } >> + } >> + >> + if (disable_aspm & ASPM_STATE_L1) >> + disable_aspm |= ASPM_STATE_L1SS; >> + >> + link->aspm_disable = disable_aspm; >> + link->clkpm_disable = disable_clkpm; >> + >> + pcie_config_aspm_link(link, policy_to_aspm_state(link)); >> + pcie_set_clkpm(link, policy_to_clkpm_state(link)); >> +out: >> + mutex_unlock(&aspm_lock); >> + up_read(&pci_bus_sem); >> + >> + return err ?: len; >> +} >> + >> +static DEVICE_ATTR_RW(aspm_disable_link_state); >> > > Since we're introducing a new sysfs interface, would it be more appropriate to rename the sysfs files to aspm_set_link_state (or something to that effect)? > > The syntax as it stands, means that to enable a state, a double negative must be used: > > echo "-L1.1" > ./aspm_disable_link_state" > vs > echo "+L1.1" > ./aspm_set_link_state > > If we avoid the double negative, the documentation about to be written will be more clear and use of the sysfs file will be more intuitive. > I think this is a valid point. Let me check and come up with a proposal. > Thanks, > Frederick Lawler > > Heiner
On 12.05.2019 03:02, Frederick Lawler wrote: > Evening, > > Heiner Kallweit wrote on 5/11/19 10:33 AM:> +static ssize_t aspm_disable_link_state_show(struct device *dev, >> + struct device_attribute *attr, >> + char *buf) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + struct pcie_link_state *link; >> + int len = 0, i; >> + >> + link = aspm_get_parent_link(pdev); >> + if (!link) >> + return -EOPNOTSUPP; >> + >> + mutex_lock(&aspm_lock); >> + >> + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { >> + const struct aspm_sysfs_state *st = aspm_sysfs_states + i; >> + >> + if (link->aspm_disable & st->disable_mask) >> + len += scnprintf(buf + len, PAGE_SIZE - len, "[%s] ", >> + st->name); >> + else >> + len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", >> + st->name); >> + } >> + >> + if (link->clkpm_disable) >> + len += scnprintf(buf + len, PAGE_SIZE - len, "[CLKPM] "); >> + else >> + len += scnprintf(buf + len, PAGE_SIZE - len, "CLKPM "); >> + >> + mutex_unlock(&aspm_lock); >> + >> + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); >> + >> + return len; >> +} > > I think it would be better to model the output to something similar to what lspci would do: > > L1.1- L1.2- L0S+ ClockPM+, etc... > > This better conveys the message that these states are enabled vs disabled. > > I'd be interested to know if the use of [STATE]/STATE pattern is used elsewhere in the kernel. If so, then I'm cool with it :) > >> + >> +static ssize_t aspm_disable_link_state_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t len) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + struct pcie_link_state *link; >> + char *buftmp = (char *)buf, *tok; >> + unsigned int disable_aspm, disable_clkpm; >> + bool first = true, add; >> + int err = 0, i; >> + >> + if (aspm_disabled) >> + return -EPERM; >> + >> + link = aspm_get_parent_link(pdev); >> + if (!link) >> + return -EOPNOTSUPP; >> + >> + down_read(&pci_bus_sem); >> + mutex_lock(&aspm_lock); >> + >> + disable_aspm = link->aspm_disable; >> + disable_clkpm = link->clkpm_disable; >> + >> + while ((tok = strsep(&buftmp, " \n")) != NULL) { >> + bool found = false; >> + >> + if (!*tok) >> + continue; >> + >> + if (first) { >> + if (!strcasecmp(tok, "none")) { >> + disable_aspm = 0; >> + disable_clkpm = 0; >> + break; >> + } >> + if (!strcasecmp(tok, "all")) { >> + disable_aspm = ASPM_STATE_ALL; >> + disable_clkpm = 1; >> + break; >> + } >> + first = false; >> + } >> + >> + if (*tok != '+' && *tok != '-') { >> + err = -EINVAL; >> + goto out; >> + } >> + >> + add = *tok++ == '+'; >> + >> + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { >> + const struct aspm_sysfs_state *st = >> + aspm_sysfs_states + i; >> + >> + if (!strcasecmp(tok, st->name)) { >> + if (add) >> + disable_aspm |= st->disable_mask; >> + else >> + disable_aspm &= ~st->disable_mask; >> + found = true; >> + break; >> + } >> + } >> + >> + if (!found && !strcasecmp(tok, "clkpm")) { >> + disable_clkpm = add ? 1 : 0; >> + found = true; >> + } >> + >> + if (!found) { >> + err = -EINVAL; >> + goto out; >> + } >> + } >> + >> + if (disable_aspm & ASPM_STATE_L1) >> + disable_aspm |= ASPM_STATE_L1SS; >> + >> + link->aspm_disable = disable_aspm; >> + link->clkpm_disable = disable_clkpm; >> + >> + pcie_config_aspm_link(link, policy_to_aspm_state(link)); >> + pcie_set_clkpm(link, policy_to_clkpm_state(link)); >> +out: >> + mutex_unlock(&aspm_lock); >> + up_read(&pci_bus_sem); >> + >> + return err ?: len; >> +} >> + >> +static DEVICE_ATTR_RW(aspm_disable_link_state); >> > > Since we're introducing a new sysfs interface, would it be more appropriate to rename the sysfs files to aspm_set_link_state (or something to that effect)? > I changed the attribute to aspm_link_states. The "set" isn't needed IMO. It's a RW attribute and that should make clear it can be used to change the state. > The syntax as it stands, means that to enable a state, a double negative must be used: > > echo "-L1.1" > ./aspm_disable_link_state" > vs > echo "+L1.1" > ./aspm_set_link_state > > If we avoid the double negative, the documentation about to be written will be more clear and use of the sysfs file will be more intuitive. > > Thanks, > Frederick Lawler > > Heiner
On 12.05.2019 03:02, Frederick Lawler wrote: > Evening, > > Heiner Kallweit wrote on 5/11/19 10:33 AM:> +static ssize_t aspm_disable_link_state_show(struct device *dev, [..] > > Since we're introducing a new sysfs interface, would it be more appropriate to rename the sysfs files to aspm_set_link_state (or something to that effect)? > > The syntax as it stands, means that to enable a state, a double negative must be used: > > echo "-L1.1" > ./aspm_disable_link_state" > vs > echo "+L1.1" > ./aspm_set_link_state > > If we avoid the double negative, the documentation about to be written will be more clear and use of the sysfs file will be more intuitive. > In addition to these more formal parts: Can you test the functionality? > Thanks, > Frederick Lawler > > Heiner
Heiner Kallweit wrote on 5/12/19 9:03 AM: > On 12.05.2019 03:02, Frederick Lawler wrote: >> Evening, >> >> Heiner Kallweit wrote on 5/11/19 10:33 AM:> +static ssize_t aspm_disable_link_state_show(struct device *dev, > [..] >> >> Since we're introducing a new sysfs interface, would it be more appropriate to rename the sysfs files to aspm_set_link_state (or something to that effect)? >> >> The syntax as it stands, means that to enable a state, a double negative must be used: >> >> echo "-L1.1" > ./aspm_disable_link_state" >> vs >> echo "+L1.1" > ./aspm_set_link_state >> >> If we avoid the double negative, the documentation about to be written will be more clear and use of the sysfs file will be more intuitive. >> > In addition to these more formal parts: Can you test the functionality? I don't have enough hardware to fully test things out. I just have 1 device with ASPM support and no switches. I'll have a go tonight with the v3 patches and report back. > >> Thanks, >> Frederick Lawler >> >> > Heiner > Frederick Lawler
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 9cb99380c..06642b7de 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -499,17 +499,13 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); void pcie_aspm_pm_state_change(struct pci_dev *pdev); void pcie_aspm_powersave_config_link(struct pci_dev *pdev); +void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev); +void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev); #else static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { } static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { } static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { } -#endif - -#ifdef CONFIG_PCIEASPM_DEBUG -void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev); -void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev); -#else static inline void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) { } static inline void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) { } #endif diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 7847be38e..530a2fbf0 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -42,6 +42,8 @@ #define ASPM_STATE_ALL (ASPM_STATE_L0S | ASPM_STATE_L1 | \ ASPM_STATE_L1SS) +static const char power_group[] = "power"; + struct aspm_latency { u32 l0s; /* L0s latency (nsec) */ u32 l1; /* L1 latency (nsec) */ @@ -1251,38 +1253,213 @@ static ssize_t clk_ctl_store(struct device *dev, static DEVICE_ATTR_RW(link_state); static DEVICE_ATTR_RW(clk_ctl); +#endif + +struct aspm_sysfs_state { + const char *name; + int disable_mask; +}; + +static const struct aspm_sysfs_state aspm_sysfs_states[] = { + { "L0S", ASPM_STATE_L0S }, + { "L1", ASPM_STATE_L1 }, + { "L1.1", ASPM_STATE_L1_1_MASK }, + { "L1.2", ASPM_STATE_L1_2_MASK }, +}; + +static struct pcie_link_state *aspm_get_parent_link(struct pci_dev *pdev) +{ + struct pci_dev *parent = pdev->bus->self; + + if (pdev->has_secondary_link) + parent = pdev; + + return parent ? parent->link_state : NULL; +} + +static bool pcie_check_aspm_endpoint(struct pci_dev *pdev) +{ + struct pcie_link_state *link; + + if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ENDPOINT) + return false; + + link = aspm_get_parent_link(pdev); + + return link && link->aspm_support; +} + +static ssize_t aspm_disable_link_state_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct pcie_link_state *link; + int len = 0, i; + + link = aspm_get_parent_link(pdev); + if (!link) + return -EOPNOTSUPP; + + mutex_lock(&aspm_lock); + + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { + const struct aspm_sysfs_state *st = aspm_sysfs_states + i; + + if (link->aspm_disable & st->disable_mask) + len += scnprintf(buf + len, PAGE_SIZE - len, "[%s] ", + st->name); + else + len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", + st->name); + } + + if (link->clkpm_disable) + len += scnprintf(buf + len, PAGE_SIZE - len, "[CLKPM] "); + else + len += scnprintf(buf + len, PAGE_SIZE - len, "CLKPM "); + + mutex_unlock(&aspm_lock); + + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); + + return len; +} + +static ssize_t aspm_disable_link_state_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct pcie_link_state *link; + char *buftmp = (char *)buf, *tok; + unsigned int disable_aspm, disable_clkpm; + bool first = true, add; + int err = 0, i; + + if (aspm_disabled) + return -EPERM; + + link = aspm_get_parent_link(pdev); + if (!link) + return -EOPNOTSUPP; + + down_read(&pci_bus_sem); + mutex_lock(&aspm_lock); + + disable_aspm = link->aspm_disable; + disable_clkpm = link->clkpm_disable; + + while ((tok = strsep(&buftmp, " \n")) != NULL) { + bool found = false; + + if (!*tok) + continue; + + if (first) { + if (!strcasecmp(tok, "none")) { + disable_aspm = 0; + disable_clkpm = 0; + break; + } + if (!strcasecmp(tok, "all")) { + disable_aspm = ASPM_STATE_ALL; + disable_clkpm = 1; + break; + } + first = false; + } + + if (*tok != '+' && *tok != '-') { + err = -EINVAL; + goto out; + } + + add = *tok++ == '+'; + + for (i = 0; i < ARRAY_SIZE(aspm_sysfs_states); i++) { + const struct aspm_sysfs_state *st = + aspm_sysfs_states + i; + + if (!strcasecmp(tok, st->name)) { + if (add) + disable_aspm |= st->disable_mask; + else + disable_aspm &= ~st->disable_mask; + found = true; + break; + } + } + + if (!found && !strcasecmp(tok, "clkpm")) { + disable_clkpm = add ? 1 : 0; + found = true; + } + + if (!found) { + err = -EINVAL; + goto out; + } + } + + if (disable_aspm & ASPM_STATE_L1) + disable_aspm |= ASPM_STATE_L1SS; + + link->aspm_disable = disable_aspm; + link->clkpm_disable = disable_clkpm; + + pcie_config_aspm_link(link, policy_to_aspm_state(link)); + pcie_set_clkpm(link, policy_to_clkpm_state(link)); +out: + mutex_unlock(&aspm_lock); + up_read(&pci_bus_sem); + + return err ?: len; +} + +static DEVICE_ATTR_RW(aspm_disable_link_state); -static char power_group[] = "power"; void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) { struct pcie_link_state *link_state = pdev->link_state; + if (pcie_check_aspm_endpoint(pdev)) + sysfs_add_file_to_group(&pdev->dev.kobj, + &dev_attr_aspm_disable_link_state.attr, power_group); + if (!link_state) return; +#ifdef CONFIG_PCIEASPM_DEBUG if (link_state->aspm_support) sysfs_add_file_to_group(&pdev->dev.kobj, &dev_attr_link_state.attr, power_group); if (link_state->clkpm_capable) sysfs_add_file_to_group(&pdev->dev.kobj, &dev_attr_clk_ctl.attr, power_group); +#endif } void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) { struct pcie_link_state *link_state = pdev->link_state; + if (pcie_check_aspm_endpoint(pdev)) + sysfs_remove_file_from_group(&pdev->dev.kobj, + &dev_attr_aspm_disable_link_state.attr, power_group); + if (!link_state) return; +#ifdef CONFIG_PCIEASPM_DEBUG if (link_state->aspm_support) sysfs_remove_file_from_group(&pdev->dev.kobj, &dev_attr_link_state.attr, power_group); if (link_state->clkpm_capable) sysfs_remove_file_from_group(&pdev->dev.kobj, &dev_attr_clk_ctl.attr, power_group); -} #endif +} static int __init pcie_aspm_disable(char *str) {
Background of this extension is a problem with the r8169 network driver. Several combinations of board chipsets and network chip versions have problems if ASPM is enabled, therefore we have to disable ASPM per default. However especially on notebooks ASPM can provide significant power-saving, therefore we want to give users the option to enable ASPM. With the new sysfs attribute users can control which ASPM link-states are disabled. This is a RFC version, therefore documentation of attribute is still missing. The attribute handling was inspired by the protocol attribute handling in drivers/media/rc/rc-main.c. Attribute syntax in a few words: none: allow all supported ASPM states all: disable all ASPM states +<state>: add state to list of disabled ASPM states -<state>: re-enable ASPM state if supported v2: - bind attribute to the endpoint Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/pci/pci.h | 8 +- drivers/pci/pcie/aspm.c | 181 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 181 insertions(+), 8 deletions(-)