Hi, On 9/11/24 2:16 PM, Hans de Goede wrote: > Hi, > > On 9/6/24 8:40 PM, Xi Pardee wrote: >> From: Xi Pardee <xi.pardee@xxxxxxxxx> >> >> Add support to ignore all LTRs before suspend and restore the previous >> LTR values after suspend. This feature could be turned off with module >> parameter ltr_ignore_all_suspend. >> >> LTR value is a mechanism for a device to indicate tolerance to access >> the corresponding resource. When system suspends, the resource is not >> available and therefore the LTR value could be ignored. Ignoring all >> LTR values prevents problematic device from blocking the system to get >> to the deepest package state during suspend. >> >> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> >> Signed-off-by: Xi Pardee <xi.pardee@xxxxxxxxx> > > Thanks, patch looks good to me: > > Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx> Oops, wrong auto-reply, what I meant is: Thank you for your patch, I've applied this patch to my review-hans branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans Note it will show up in my review-hans branch once I've pushed my local branch there, which might take a while. Once I've run some tests on this branch the patches there will be added to the platform-drivers-x86/for-next branch and eventually will be included in the pdx86 pull-request to Linus for the next merge-window. Regards, Hans >> v2: >> - Add more details to commit message >> - Fix format: ltr->LTR, S0IX->S0ix, space between name and email >> >> --- >> drivers/platform/x86/intel/pmc/core.c | 53 +++++++++++++++++++++++++++ >> drivers/platform/x86/intel/pmc/core.h | 2 + >> 2 files changed, 55 insertions(+) >> >> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c >> index 01ae71c6df59..0ec703af16a4 100644 >> --- a/drivers/platform/x86/intel/pmc/core.c >> +++ b/drivers/platform/x86/intel/pmc/core.c >> @@ -714,6 +714,49 @@ static int pmc_core_s0ix_blocker_show(struct seq_file *s, void *unused) >> } >> DEFINE_SHOW_ATTRIBUTE(pmc_core_s0ix_blocker); >> >> +static void pmc_core_ltr_ignore_all(struct pmc_dev *pmcdev) >> +{ >> + unsigned int i; >> + >> + for (i = 0; i < ARRAY_SIZE(pmcdev->pmcs); i++) { >> + struct pmc *pmc; >> + u32 ltr_ign; >> + >> + pmc = pmcdev->pmcs[i]; >> + if (!pmc) >> + continue; >> + >> + guard(mutex)(&pmcdev->lock); >> + pmc->ltr_ign = pmc_core_reg_read(pmc, pmc->map->ltr_ignore_offset); >> + >> + /* ltr_ignore_max is the max index value for LTR ignore register */ >> + ltr_ign = pmc->ltr_ign | GENMASK(pmc->map->ltr_ignore_max, 0); >> + pmc_core_reg_write(pmc, pmc->map->ltr_ignore_offset, ltr_ign); >> + } >> + >> + /* >> + * Ignoring ME during suspend is blocking platforms with ADL PCH to get to >> + * deeper S0ix substate. >> + */ >> + pmc_core_send_ltr_ignore(pmcdev, 6, 0); >> +} >> + >> +static void pmc_core_ltr_restore_all(struct pmc_dev *pmcdev) >> +{ >> + unsigned int i; >> + >> + for (i = 0; i < ARRAY_SIZE(pmcdev->pmcs); i++) { >> + struct pmc *pmc; >> + >> + pmc = pmcdev->pmcs[i]; >> + if (!pmc) >> + continue; >> + >> + guard(mutex)(&pmcdev->lock); >> + pmc_core_reg_write(pmc, pmc->map->ltr_ignore_offset, pmc->ltr_ign); >> + } >> +} >> + >> static inline u64 adjust_lpm_residency(struct pmc *pmc, u32 offset, >> const int lpm_adj_x2) >> { >> @@ -1479,6 +1522,10 @@ static bool warn_on_s0ix_failures; >> module_param(warn_on_s0ix_failures, bool, 0644); >> MODULE_PARM_DESC(warn_on_s0ix_failures, "Check and warn for S0ix failures"); >> >> +static bool ltr_ignore_all_suspend = true; >> +module_param(ltr_ignore_all_suspend, bool, 0644); >> +MODULE_PARM_DESC(ltr_ignore_all_suspend, "Ignore all LTRs during suspend"); >> + >> static __maybe_unused int pmc_core_suspend(struct device *dev) >> { >> struct pmc_dev *pmcdev = dev_get_drvdata(dev); >> @@ -1488,6 +1535,9 @@ static __maybe_unused int pmc_core_suspend(struct device *dev) >> if (pmcdev->suspend) >> pmcdev->suspend(pmcdev); >> >> + if (ltr_ignore_all_suspend) >> + pmc_core_ltr_ignore_all(pmcdev); >> + >> /* Check if the syspend will actually use S0ix */ >> if (pm_suspend_via_firmware()) >> return 0; >> @@ -1594,6 +1644,9 @@ static __maybe_unused int pmc_core_resume(struct device *dev) >> { >> struct pmc_dev *pmcdev = dev_get_drvdata(dev); >> >> + if (ltr_ignore_all_suspend) >> + pmc_core_ltr_restore_all(pmcdev); >> + >> if (pmcdev->resume) >> return pmcdev->resume(pmcdev); >> >> diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h >> index ea04de7eb9e8..e862ea88b816 100644 >> --- a/drivers/platform/x86/intel/pmc/core.h >> +++ b/drivers/platform/x86/intel/pmc/core.h >> @@ -372,6 +372,7 @@ struct pmc_info { >> * @map: pointer to pmc_reg_map struct that contains platform >> * specific attributes >> * @lpm_req_regs: List of substate requirements >> + * @ltr_ign: Holds LTR ignore data while suspended >> * >> * pmc contains info about one power management controller device. >> */ >> @@ -380,6 +381,7 @@ struct pmc { >> void __iomem *regbase; >> const struct pmc_reg_map *map; >> u32 *lpm_req_regs; >> + u32 ltr_ign; >> }; >> >> /** >
