| Message ID | 1481590462-9981-1-git-send-email-subhashj@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Mon, Dec 12, 2016 at 04:54:20PM -0800, Subhash Jadavani wrote: > UFS device and link can be put in multiple different low power modes hence > UFS driver supports multiple different low power modes. By default UFS > driver selects the default (optimal) low power mode (which gives moderate > power savings and have relatively less enter and exit latencies) but > we might have to tune this default power mode for different chipset > platforms to meet the low power requirements/goals. Hence this patch > adds option to change default UFS low power mode (level). > > Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org> > Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> > --- > .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 10 ++++++ > drivers/scsi/ufs/ufshcd-pltfrm.c | 14 ++++++++ > drivers/scsi/ufs/ufshcd.c | 39 ++++++++++++++++++++++ > drivers/scsi/ufs/ufshcd.h | 4 +-- > 4 files changed, 65 insertions(+), 2 deletions(-) > > diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > index a99ed55..c3836c5 100644 > --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > @@ -41,6 +41,14 @@ Optional properties: > -lanes-per-direction : number of lanes available per direction - either 1 or 2. > Note that it is assume same number of lanes is used both > directions at once. If not specified, default is 2 lanes per direction. > +- rpm-level : UFS Runtime power management level. Following PM levels are supported: > + 0 - Both UFS device and Link in active state (Highest power consumption) > + 1 - UFS device in active state but Link in Hibern8 state > + 2 - UFS device in Sleep state but Link in active state > + 3 - UFS device in Sleep state and Link in hibern8 state (default PM level) > + 4 - UFS device in Power-down state and Link in Hibern8 state > + 5 - UFS device in Power-down state and Link in OFF state (Lowest power consumption) > +- spm-level : UFS System power management level. Allowed PM levels are same as rpm-level. This looks like you are putting policy for Linux into DT. What I would expect to see here is disabling of states that don't work due to some h/w limitation. Otherwise, it is a user decision for what modes to go into. Also, I think link and device states should be separate. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2016-12-13 12:04, Rob Herring wrote: > On Mon, Dec 12, 2016 at 04:54:20PM -0800, Subhash Jadavani wrote: >> UFS device and link can be put in multiple different low power modes >> hence >> UFS driver supports multiple different low power modes. By default UFS >> driver selects the default (optimal) low power mode (which gives >> moderate >> power savings and have relatively less enter and exit latencies) but >> we might have to tune this default power mode for different chipset >> platforms to meet the low power requirements/goals. Hence this patch >> adds option to change default UFS low power mode (level). >> >> Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org> >> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> >> --- >> .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 10 ++++++ >> drivers/scsi/ufs/ufshcd-pltfrm.c | 14 ++++++++ >> drivers/scsi/ufs/ufshcd.c | 39 >> ++++++++++++++++++++++ >> drivers/scsi/ufs/ufshcd.h | 4 +-- >> 4 files changed, 65 insertions(+), 2 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> index a99ed55..c3836c5 100644 >> --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> @@ -41,6 +41,14 @@ Optional properties: >> -lanes-per-direction : number of lanes available per direction - >> either 1 or 2. >> Note that it is assume same number of lanes is used both >> directions at once. If not specified, default is 2 lanes per >> direction. >> +- rpm-level : UFS Runtime power management level. Following PM >> levels are supported: >> + 0 - Both UFS device and Link in active state (Highest power >> consumption) >> + 1 - UFS device in active state but Link in Hibern8 state >> + 2 - UFS device in Sleep state but Link in active state >> + 3 - UFS device in Sleep state and Link in hibern8 state (default >> PM level) >> + 4 - UFS device in Power-down state and Link in Hibern8 state >> + 5 - UFS device in Power-down state and Link in OFF state (Lowest >> power consumption) >> +- spm-level : UFS System power management level. Allowed PM levels >> are same as rpm-level. > > This looks like you are putting policy for Linux into DT. > > What I would expect to see here is disabling of states that don't work > due to some h/w limitation. Otherwise, it is a user decision for what > modes to go into. Also, I think link and device states should be > separate. Yes, generally default level (3) is good enough (and recommended) for all platforms and most likely user is only expected to change this if they see issues (most H/W) on their platform or they want even more aggressive power state (level-4 or level-5) and ready to take the performance hit associated with resume latencies. Also, I think it is better to keep Link and device states tied, one reason is that we can't keep device in sleep/active state when Link is in OFF state. > > Rob
On Tue, Dec 13, 2016 at 2:16 PM, Subhash Jadavani <subhashj@codeaurora.org> wrote: > On 2016-12-13 12:04, Rob Herring wrote: >> >> On Mon, Dec 12, 2016 at 04:54:20PM -0800, Subhash Jadavani wrote: >>> >>> UFS device and link can be put in multiple different low power modes >>> hence >>> UFS driver supports multiple different low power modes. By default UFS >>> driver selects the default (optimal) low power mode (which gives moderate >>> power savings and have relatively less enter and exit latencies) but >>> we might have to tune this default power mode for different chipset >>> platforms to meet the low power requirements/goals. Hence this patch >>> adds option to change default UFS low power mode (level). >>> >>> Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org> >>> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> >>> --- >>> .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 10 ++++++ >>> drivers/scsi/ufs/ufshcd-pltfrm.c | 14 ++++++++ >>> drivers/scsi/ufs/ufshcd.c | 39 >>> ++++++++++++++++++++++ >>> drivers/scsi/ufs/ufshcd.h | 4 +-- >>> 4 files changed, 65 insertions(+), 2 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>> b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>> index a99ed55..c3836c5 100644 >>> --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>> +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>> @@ -41,6 +41,14 @@ Optional properties: >>> -lanes-per-direction : number of lanes available per direction - >>> either 1 or 2. >>> Note that it is assume same number of lanes is >>> used both >>> directions at once. If not specified, default >>> is 2 lanes per direction. >>> +- rpm-level : UFS Runtime power management level. Following >>> PM levels are supported: >>> + 0 - Both UFS device and Link in active state >>> (Highest power consumption) >>> + 1 - UFS device in active state but Link in >>> Hibern8 state >>> + 2 - UFS device in Sleep state but Link in >>> active state >>> + 3 - UFS device in Sleep state and Link in >>> hibern8 state (default PM level) >>> + 4 - UFS device in Power-down state and Link in >>> Hibern8 state >>> + 5 - UFS device in Power-down state and Link in >>> OFF state (Lowest power consumption) >>> +- spm-level : UFS System power management level. Allowed PM >>> levels are same as rpm-level. >> >> >> This looks like you are putting policy for Linux into DT. >> >> What I would expect to see here is disabling of states that don't work >> due to some h/w limitation. Otherwise, it is a user decision for what >> modes to go into. Also, I think link and device states should be >> separate. > > > Yes, generally default level (3) is good enough (and recommended) for all > platforms and most likely user is only expected to change this if they see > issues (most H/W) on their platform or they want even more aggressive power > state (level-4 or level-5) and ready to take the performance hit associated > with resume latencies. What latencies can be tolerated is going to depend on the application and could vary while running, so putting in DT doesn't make sense. I would break down settings like this: broken h/w -> DT user tuning/config -> sysfs sensible defaults -> driver > Also, I think it is better to keep Link and device states tied, one reason > is that we can't keep device in sleep/active state when Link is in OFF > state. The driver can tie the states to together if needed. Just document what's broken in DT and let the driver make decisions. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2016-12-19 10:38, Rob Herring wrote: > On Tue, Dec 13, 2016 at 2:16 PM, Subhash Jadavani > <subhashj@codeaurora.org> wrote: >> On 2016-12-13 12:04, Rob Herring wrote: >>> >>> On Mon, Dec 12, 2016 at 04:54:20PM -0800, Subhash Jadavani wrote: >>>> >>>> UFS device and link can be put in multiple different low power modes >>>> hence >>>> UFS driver supports multiple different low power modes. By default >>>> UFS >>>> driver selects the default (optimal) low power mode (which gives >>>> moderate >>>> power savings and have relatively less enter and exit latencies) but >>>> we might have to tune this default power mode for different chipset >>>> platforms to meet the low power requirements/goals. Hence this patch >>>> adds option to change default UFS low power mode (level). >>>> >>>> Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org> >>>> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> >>>> --- >>>> .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 10 ++++++ >>>> drivers/scsi/ufs/ufshcd-pltfrm.c | 14 ++++++++ >>>> drivers/scsi/ufs/ufshcd.c | 39 >>>> ++++++++++++++++++++++ >>>> drivers/scsi/ufs/ufshcd.h | 4 +-- >>>> 4 files changed, 65 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>>> b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>>> index a99ed55..c3836c5 100644 >>>> --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>>> +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >>>> @@ -41,6 +41,14 @@ Optional properties: >>>> -lanes-per-direction : number of lanes available per direction - >>>> either 1 or 2. >>>> Note that it is assume same number of >>>> lanes is >>>> used both >>>> directions at once. If not specified, >>>> default >>>> is 2 lanes per direction. >>>> +- rpm-level : UFS Runtime power management level. >>>> Following >>>> PM levels are supported: >>>> + 0 - Both UFS device and Link in active >>>> state >>>> (Highest power consumption) >>>> + 1 - UFS device in active state but Link in >>>> Hibern8 state >>>> + 2 - UFS device in Sleep state but Link in >>>> active state >>>> + 3 - UFS device in Sleep state and Link in >>>> hibern8 state (default PM level) >>>> + 4 - UFS device in Power-down state and >>>> Link in >>>> Hibern8 state >>>> + 5 - UFS device in Power-down state and >>>> Link in >>>> OFF state (Lowest power consumption) >>>> +- spm-level : UFS System power management level. Allowed >>>> PM >>>> levels are same as rpm-level. >>> >>> >>> This looks like you are putting policy for Linux into DT. >>> >>> What I would expect to see here is disabling of states that don't >>> work >>> due to some h/w limitation. Otherwise, it is a user decision for what >>> modes to go into. Also, I think link and device states should be >>> separate. >> >> >> Yes, generally default level (3) is good enough (and recommended) for >> all >> platforms and most likely user is only expected to change this if they >> see >> issues (most H/W) on their platform or they want even more aggressive >> power >> state (level-4 or level-5) and ready to take the performance hit >> associated >> with resume latencies. > > What latencies can be tolerated is going to depend on the application > and could vary while running, so putting in DT doesn't make sense. I > would break down settings like this: > > broken h/w -> DT > user tuning/config -> sysfs > sensible defaults -> driver Make sense. we already have #2 and #3 in place, will rework this patch so we have a way to specify what is broken in h/w. > >> Also, I think it is better to keep Link and device states tied, one >> reason >> is that we can't keep device in sleep/active state when Link is in OFF >> state. > > The driver can tie the states to together if needed. Just document > what's broken in DT and let the driver make decisions. Yes, agreed. will rework this patch so we have a way to specify what is broken in h/w and separate the device and link states (something like broken-hibern8, broken-sleep etc.) Thanks for the suggestions. > > Rob
diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt index a99ed55..c3836c5 100644 --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt @@ -41,6 +41,14 @@ Optional properties: -lanes-per-direction : number of lanes available per direction - either 1 or 2. Note that it is assume same number of lanes is used both directions at once. If not specified, default is 2 lanes per direction. +- rpm-level : UFS Runtime power management level. Following PM levels are supported: + 0 - Both UFS device and Link in active state (Highest power consumption) + 1 - UFS device in active state but Link in Hibern8 state + 2 - UFS device in Sleep state but Link in active state + 3 - UFS device in Sleep state and Link in hibern8 state (default PM level) + 4 - UFS device in Power-down state and Link in Hibern8 state + 5 - UFS device in Power-down state and Link in OFF state (Lowest power consumption) +- spm-level : UFS System power management level. Allowed PM levels are same as rpm-level. Note: If above properties are not defined it can be assumed that the supply regulators or clocks are always on. @@ -66,4 +74,6 @@ Example: freq-table-hz = <100000000 200000000>, <0 0>, <0 0>; phys = <&ufsphy1>; phy-names = "ufsphy"; + rpm-level = <3>; + spm-level = <5>; }; diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c index a72a4ba..896943d 100644 --- a/drivers/scsi/ufs/ufshcd-pltfrm.c +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c @@ -223,6 +223,19 @@ static int ufshcd_parse_regulator_info(struct ufs_hba *hba) return err; } +static void ufshcd_parse_pm_levels(struct ufs_hba *hba) +{ + struct device *dev = hba->dev; + struct device_node *np = dev->of_node; + + if (np) { + if (of_property_read_u32(np, "rpm-level", &hba->rpm_lvl)) + hba->rpm_lvl = -1; + if (of_property_read_u32(np, "spm-level", &hba->spm_lvl)) + hba->spm_lvl = -1; + } +} + #ifdef CONFIG_PM /** * ufshcd_pltfrm_suspend - suspend power management function @@ -342,6 +355,7 @@ int ufshcd_pltfrm_init(struct platform_device *pdev, goto dealloc_host; } + ufshcd_parse_pm_levels(hba); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 470ea99..43f9b44 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -191,6 +191,22 @@ enum { return ufs_pm_lvl_states[lvl].link_state; } +static inline enum ufs_pm_level +ufs_get_desired_pm_lvl_for_dev_link_state(enum ufs_dev_pwr_mode dev_state, + enum uic_link_state link_state) +{ + enum ufs_pm_level lvl; + + for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++) { + if ((ufs_pm_lvl_states[lvl].dev_state == dev_state) && + (ufs_pm_lvl_states[lvl].link_state == link_state)) + return lvl; + } + + /* if no match found, return the level 0 */ + return UFS_PM_LVL_0; +} + static struct ufs_dev_fix ufs_fixups[] = { /* UFS cards deviations table */ UFS_FIX(UFS_VENDOR_SAMSUNG, UFS_ANY_MODEL, @@ -215,6 +231,14 @@ enum { END_FIX }; +static inline bool ufshcd_is_valid_pm_lvl(int lvl) +{ + if (lvl >= 0 && lvl < ARRAY_SIZE(ufs_pm_lvl_states)) + return true; + else + return false; +} + static void ufshcd_tmc_handler(struct ufs_hba *hba); static void ufshcd_async_scan(void *data, async_cookie_t cookie); static int ufshcd_reset_and_restore(struct ufs_hba *hba); @@ -7290,6 +7314,21 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) ufshcd_clkscaling_init_sysfs(hba); } + /* + * If rpm_lvl and and spm_lvl are not already set to valid levels, + * set the default power management level for UFS runtime and system + * suspend. Default power saving mode selected is keeping UFS link in + * Hibern8 state and UFS device in sleep. + */ + if (!ufshcd_is_valid_pm_lvl(hba->rpm_lvl)) + hba->rpm_lvl = ufs_get_desired_pm_lvl_for_dev_link_state( + UFS_SLEEP_PWR_MODE, + UIC_LINK_HIBERN8_STATE); + if (!ufshcd_is_valid_pm_lvl(hba->spm_lvl)) + hba->spm_lvl = ufs_get_desired_pm_lvl_for_dev_link_state( + UFS_SLEEP_PWR_MODE, + UIC_LINK_HIBERN8_STATE); + /* Hold auto suspend until async scan completes */ pm_runtime_get_sync(dev); diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 787323b..97fbe4a 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -432,9 +432,9 @@ struct ufs_hba { enum ufs_dev_pwr_mode curr_dev_pwr_mode; enum uic_link_state uic_link_state; /* Desired UFS power management level during runtime PM */ - enum ufs_pm_level rpm_lvl; + int rpm_lvl; /* Desired UFS power management level during system PM */ - enum ufs_pm_level spm_lvl; + int spm_lvl; struct device_attribute rpm_lvl_attr; struct device_attribute spm_lvl_attr; int pm_op_in_progress;