PCI/PM: Always disable PTM for all devices during
cover PCI/PM: Always disable PTM for all devices during
From: Bjorn Helgaas <[email protected]>
We currently disable PTM for Root Ports during suspend. Leaving PTM enabled for downstream devices causes UR errors if they send PTM Requests. The intent of this series is to:
- Unconditionally disable PTM during suspend (even if the driver saves its own state) by moving the disable from pci_prepare_to_sleep() to pci_pm_suspend().
- Disable PTM for all devices by removing the Root Port condition.
- Manually set PTM Enable when restoring PTM state because suspend saves the PTM state *after* disabling PTM.
This series is intended to replace Rajvi's second patch, so we would end up with this:
Rajvi PCI/PM: Simplify pci_pm_suspend_noirq() Bjorn PCI/PTM: Preserve PTM Root Select Bjorn PCI/PTM: Enable PTM when restoring state Bjorn PCI/PM: Always disable PTM for all devices during suspend Bjorn PCI/PTM: Cache PTM Capability offset
Please comment!
Bjorn Helgaas (4):
PCI/PTM: Preserve PTM Root Select
PCI/PTM: Enable PTM when restoring state
PCI/PM: Always disable PTM for all devices during suspend PCI/PTM: Cache PTM Capability offset
drivers/pci/pci-driver.c | 8 ++++++ drivers/pci/pci.c | 20 -------------- drivers/pci/pcie/ptm.c | 56 +++++++++++++++++++--------------------- include/linux/pci.h | 1 + 4 files changed, 35 insertions(+), 50 deletions(-)
Signature · 1 line
2.25.1
PATCH 1/4 PCI/PTM: Preserve PTM Root Select
From: Bjorn Helgaas <[email protected]>
When disabling PTM, there's no need to clear the Root Select bit. We disable PTM during suspend, and we want to re-enable it during resume. Clearing Root Select here makes re-enabling more complicated.
Per PCIe r6.0, sec 7.9.15.3, "When set, if the PTM Enable bit is also Set, this Time Source is the PTM Root," so if PTM Enable is cleared, the value of Root Select should be irrelevant.
Preserve Root Select to simplify re-enabling PTM.
--- drivers/pci/pcie/ptm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/pci/pcie/ptm.c +1 -1
@@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev)return ;pci_read_config_word (dev, ptm +PCI_PTM_CTRL , &ctrl); - ctrl &= ~(PCI_PTM_CTRL_ENABLE |PCI_PTM_CTRL_ROOT ); + ctrl &= ~PCI_PTM_CTRL_ENABLE ;pci_write_config_word (dev, ptm +PCI_PTM_CTRL , ctrl); }
Signature · 1 line
2.25.1
Re: [PATCH 1/4] PCI/PTM: Preserve PTM Root Select
Quoted 5 lines · Bjorn Helgaas
From: Bjorn Helgaas <[email protected]>
When disabling PTM, there's no need to clear the Root Select bit. We disable PTM during suspend, and we want to re-enable it during resume. Clearing Root Select here makes re-enabling more complicated.
Currently, it looks like we disable PCI_PTM_CTRL_ROOT in pci_disable_ptm(), but not enable it in pci_enable_ptm(). Do you know this did not trigger an issue?
Also, you mentioned that it is complicated to enable it, can you add some details?
Quoted 26 lines
Per PCIe r6.0, sec 7.9.15.3, "When set, if the PTM Enable bit is also Set, this Time Source is the PTM Root," so if PTM Enable is cleared, the value of Root Select should be irrelevant.
Preserve Root Select to simplify re-enabling PTM.
Signed-off-by Bjorn Helgaas <[email protected]>Cc David E. Box <[email protected]>--- drivers/pci/pcie/ptm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/pci/pcie/ptm.c +1
-1@@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev)return ;pci_read_config_word (dev, ptm +PCI_PTM_CTRL , &ctrl); - ctrl &= ~(PCI_PTM_CTRL_ENABLE |PCI_PTM_CTRL_ROOT ); + ctrl &= ~PCI_PTM_CTRL_ENABLE ;pci_write_config_word (dev, ptm +PCI_PTM_CTRL , ctrl); }
Signature · 2 lines
Sathyanarayanan Kuppuswamy Linux Kernel Developer
Re: [PATCH 1/4] PCI/PTM: Preserve PTM Root Select
Quoted 10 lines · Sathyanarayanan Kuppuswamy
Quoted 5 lines · Bjorn Helgaas
From: Bjorn Helgaas <[email protected]>
When disabling PTM, there's no need to clear the Root Select bit. We disable PTM during suspend, and we want to re-enable it during resume. Clearing Root Select here makes re-enabling more complicated.
Currently, it looks like we disable
PCI_PTM_CTRL_ROOTinpci_disable_ptm(), but not enable it inpci_enable_ptm(). Do you know this did not trigger an issue?
For Root Ports and Switches, we enable PTM (and set Root Select when appropriate) during enumeration in pci_ptm_init(). This is based on the assumption that enabling PTM in Root Ports and Switches is a no-op unless there's an Endpoint that generates PTM Requests. (It turns out that's not quite true, because Kai-Heng's bug report [1] shows the 08:00.0 Switch sending PTM Requests even though no Endpoint even has a PTM Capability.)
If we didn't enable PTM in Root Ports and Switches during enumeration, we'd have to walk the whole path and enable them when enabling PTM for an Endpoint.
pci_enable_ptm() currently only works for Endpoints, which cannot be PTM Roots, so it never has to set PCI_PTM_CTRL_ROOT.
If we clear PCI_PTM_CTRL_ROOT in pci_disable_ptm(), it will never get set again unless we re-enumerate the Root Port.
Thanks for asking this, because it reminds me why I didn't add pci_enable_ptm() calls in the resume paths! That would make them parallel with the suspend paths, which would definitely be nice. But we would have to rework pci_enable_ptm() to work for Root Ports and Switch Ports as well. I think we *could* do that. What do you think?
Regardless of that question, I think it's unnecessary to clear PCI_PTM_CTRL_ROOT in pci_disable_ptm(), so we should leave it alone.
[1] https://bugzilla.kernel.org/show_bug.cgi?id=215453
Quoted 32 lines
Also, you mentioned that it is complicated to enable it, can you add some details?
Quoted 25 lines
Per PCIe r6.0, sec 7.9.15.3, "When set, if the PTM Enable bit is also Set, this Time Source is the PTM Root," so if PTM Enable is cleared, the value of Root Select should be irrelevant.
Preserve Root Select to simplify re-enabling PTM.
Signed-off-by Bjorn Helgaas <[email protected]>Cc David E. Box <[email protected]>--- drivers/pci/pcie/ptm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/pci/pcie/ptm.c +1
-1@@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev)return ;pci_read_config_word (dev, ptm +PCI_PTM_CTRL , &ctrl); - ctrl &= ~(PCI_PTM_CTRL_ENABLE |PCI_PTM_CTRL_ROOT ); + ctrl &= ~PCI_PTM_CTRL_ENABLE ;pci_write_config_word (dev, ptm +PCI_PTM_CTRL , ctrl); }Signature · 2 lines
Sathyanarayanan Kuppuswamy Linux Kernel Developer
Re: [PATCH 1/4] PCI/PTM: Preserve PTM Root Select
Hi Bjorn,
Quoted 24 lines · Bjorn Helgaas
Quoted 10 lines · Sathyanarayanan Kuppuswamy
Quoted 5 lines · Bjorn Helgaas
From: Bjorn Helgaas <[email protected]>
When disabling PTM, there's no need to clear the Root Select bit. We disable PTM during suspend, and we want to re-enable it during resume. Clearing Root Select here makes re-enabling more complicated.
Currently, it looks like we disable
PCI_PTM_CTRL_ROOTinpci_disable_ptm(), but not enable it inpci_enable_ptm(). Do you know this did not trigger an issue?For Root Ports and Switches, we enable PTM (and set Root Select when appropriate) during enumeration in
pci_ptm_init(). This is based on the assumption that enabling PTM in Root Ports and Switches is a no-op unless there's an Endpoint that generates PTM Requests. (It turns out that's not quite true, because Kai-Heng's bug report [1] shows the 08:00.0 Switch sending PTM Requests even though no Endpoint even has a PTM Capability.)If we didn't enable PTM in Root Ports and Switches during enumeration, we'd have to walk the whole path and enable them when enabling PTM for an Endpoint.
Quoted 5 lines
pci_enable_ptm()currently only works for Endpoints, which cannot be PTM Roots, so it never has to setPCI_PTM_CTRL_ROOT.If we clear
PCI_PTM_CTRL_ROOTinpci_disable_ptm(), it will never get set again unless we re-enumerate the Root Port.
Thanks for clarifying.
Quoted 6 lines
Thanks for asking this, because it reminds me why I didn't add
pci_enable_ptm()calls in the resume paths! That would make them parallel with the suspend paths, which would definitely be nice. But we would have to reworkpci_enable_ptm()to work for Root Ports and Switch Ports as well. I think we *could* do that. What do you think?
IMO, the code will look better if we keep the suspend and resume paths in sync. Since we are calling pci_disable_ptm() in suspend path, it makes sense to call pci_enable_ptm() in resume path.
Making the pci_enable_ptm() handle root and upstream ports should not be very complicated, right?
Quoted 3 lines
Regardless of that question, I think it's unnecessary to clear
PCI_PTM_CTRL_ROOTinpci_disable_ptm(), so we should leave it alone.
I agree with you. We should not touch PCI_PTM_CTRL_ROOT in pci_disable_ptm().
Quoted 35 lines
[1] https://bugzilla.kernel.org/show_bug.cgi?id=215453
Quoted 32 lines
Also, you mentioned that it is complicated to enable it, can you add some details?
Quoted 25 lines
Per PCIe r6.0, sec 7.9.15.3, "When set, if the PTM Enable bit is also Set, this Time Source is the PTM Root," so if PTM Enable is cleared, the value of Root Select should be irrelevant.
Preserve Root Select to simplify re-enabling PTM.
Signed-off-by Bjorn Helgaas <[email protected]>Cc David E. Box <[email protected]>--- drivers/pci/pcie/ptm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/pci/pcie/ptm.c +1
-1@@ -42,7 +42,7 @@ void pci_disable_ptm(struct pci_dev *dev)return ;pci_read_config_word (dev, ptm +PCI_PTM_CTRL , &ctrl); - ctrl &= ~(PCI_PTM_CTRL_ENABLE |PCI_PTM_CTRL_ROOT ); + ctrl &= ~PCI_PTM_CTRL_ENABLE ;pci_write_config_word (dev, ptm +PCI_PTM_CTRL , ctrl); }Signature · 2 lines
Sathyanarayanan Kuppuswamy Linux Kernel Developer
Signature · 2 lines
Sathyanarayanan Kuppuswamy Linux Kernel Developer
Re: [PATCH 1/4] PCI/PTM: Preserve PTM Root Select
Quoted 20 lines · Sathyanarayanan Kuppuswamy
Quoted 11 lines · Bjorn Helgaas
Quoted 10 lines · Sathyanarayanan Kuppuswamy
Quoted 5 lines · Bjorn Helgaas
From: Bjorn Helgaas <[email protected]>
When disabling PTM, there's no need to clear the Root Select bit. We disable PTM during suspend, and we want to re-enable it during resume. Clearing Root Select here makes re-enabling more complicated.
Currently, it looks like we disable
PCI_PTM_CTRL_ROOTinpci_disable_ptm(), but not enable it inpci_enable_ptm(). Do you know this did not trigger an issue?...
Quoted 5 lines
Thanks for asking this, because it reminds me why I didn't add
pci_enable_ptm()calls in the resume paths! That would make them parallel with the suspend paths, which would definitely be nice. But we would have to reworkpci_enable_ptm()to work for Root Ports and Switch Ports as well. I think we *could* do that. What do you think?
Quoted 6 lines
IMO, the code will look better if we keep the suspend and resume paths in sync. Since we are calling
pci_disable_ptm()in suspend path, it makes sense to callpci_enable_ptm()in resume path.Making the
pci_enable_ptm()handle root and upstream ports should not be very complicated, right?
I took a stab at it. pci_enable_ptm() is getting kind of ugly, but maybe it's better overall. I'll post it and you can see what you think.
PATCH 2/4 PCI/PTM: Enable PTM when restoring state
In reply to Bjorn HelgaasFrom: Bjorn Helgaas <[email protected]>
The suspend path may disable PTM before saving config state, which means the PCI_PTM_CTRL_ENABLE bit in the saved state may be cleared even though we want PTM to be enabled when resuming.
If "dev->ptm_enabled" is set, it means PTM should be enabled, so make sure PCI_PTM_CTRL_ENABLE is set when restoring the PTM state.
--- drivers/pci/pcie/ptm.c | 8 ++++++++ 1 file changed, 8 insertions(+)
drivers/pci/pcie/ptm.c +8 -0
@@ -82,6 +82,14 @@ void pci_restore_ptm_state(struct pci_dev *dev)return ; cap = (u16 *)&save_state->cap.data[0 ]; + +/* +* The suspend path may disable PTM before saving config state. +* Make sure PCI_PTM_CTRL_ENABLE is set if PTM should be enabled. +*/ +if (dev->ptm_enabled) + *cap |=PCI_PTM_CTRL_ENABLE ; +pci_write_config_word (dev, ptm +PCI_PTM_CTRL , *cap); }
Signature · 1 line
2.25.1
Re: [PATCH 2/4] PCI/PTM: Enable PTM when restoring state
Quoted 5 lines · Bjorn Helgaas
From: Bjorn Helgaas <[email protected]>
The suspend path may disable PTM before saving config state, which means the
PCI_PTM_CTRL_ENABLEbit in the saved state may be cleared even though we want PTM to be enabled when resuming.
If suspend is disabling PTM separately, why not enable it during the resume operation? Why club it with PTM state restoration?
Quoted 28 lines
If "
dev->ptm_enabled" is set, it means PTM should be enabled, so make surePCI_PTM_CTRL_ENABLEis set when restoring the PTM state.Signed-off-by Bjorn Helgaas <[email protected]>--- drivers/pci/pcie/ptm.c | 8 ++++++++ 1 file changed, 8 insertions(+)drivers/pci/pcie/ptm.c +8
-0@@ -82,6 +82,14 @@ void pci_restore_ptm_state(struct pci_dev *dev)return ; cap = (u16 *)&save_state->cap.data[0 ]; + +/* +* The suspend path may disable PTM before saving config state. +* Make sure PCI_PTM_CTRL_ENABLE is set if PTM should be enabled. +*/ +if (dev->ptm_enabled) + *cap |=PCI_PTM_CTRL_ENABLE ; +pci_write_config_word (dev, ptm +PCI_PTM_CTRL , *cap); }
Signature · 2 lines
Sathyanarayanan Kuppuswamy Linux Kernel Developer
Re: [PATCH 2/4] PCI/PTM: Enable PTM when restoring state
Quoted 9 lines · Sathyanarayanan Kuppuswamy
Quoted 5 lines · Bjorn Helgaas
From: Bjorn Helgaas <[email protected]>
The suspend path may disable PTM before saving config state, which means the
PCI_PTM_CTRL_ENABLEbit in the saved state may be cleared even though we want PTM to be enabled when resuming.If suspend is disabling PTM separately, why not enable it during the resume operation? Why club it with PTM state restoration?
The long answer is in my previous reply [1]. The short answer is that pci_enable_ptm() only works with Endpoints, so if we enable PTM in the resume path, we need to rework it to handle Root Ports and Switch Ports as well.
[1] https://lore.kernel.org/r/20220902203848.GA370638@bhelgaas
Quoted 31 lines
Quoted 27 lines
If "
dev->ptm_enabled" is set, it means PTM should be enabled, so make surePCI_PTM_CTRL_ENABLEis set when restoring the PTM state.Signed-off-by Bjorn Helgaas <[email protected]>--- drivers/pci/pcie/ptm.c | 8 ++++++++ 1 file changed, 8 insertions(+)drivers/pci/pcie/ptm.c +8
-0@@ -82,6 +82,14 @@ void pci_restore_ptm_state(struct pci_dev *dev)return ; cap = (u16 *)&save_state->cap.data[0 ]; + +/* +* The suspend path may disable PTM before saving config state. +* Make sure PCI_PTM_CTRL_ENABLE is set if PTM should be enabled. +*/ +if (dev->ptm_enabled) + *cap |=PCI_PTM_CTRL_ENABLE ; +pci_write_config_word (dev, ptm +PCI_PTM_CTRL , *cap); }Signature · 2 lines
Sathyanarayanan Kuppuswamy Linux Kernel Developer
PATCH 3/4 PCI/PM: Always disable PTM for all devices during suspend
In reply to Bjorn HelgaasFrom: Bjorn Helgaas <[email protected]>
We want to disable PTM on Root Ports because that allows some chips, e.g., Intel mobile chips since Coffee Lake, to enter a lower-power PM state.
That means we also have to disable PTM on downstream devices. PCIe r6.0, sec 2.2.8, recommends that functions support generation of messages in non-D0 states, so we have to assume Switch Upstream Ports or Endpoints may send PTM Requests while in D1, D2, and D3hot. A PTM message received by a Downstream Port (including a Root Port) with PTM disabled must be treated as an Unsupported Request (sec 6.21.3).
PTM was previously disabled only for Root Ports, and it was disabled in pci_prepare_to_sleep(), which is not called at all if a driver supports legacy PM or does its own state saving.
Instead, disable PTM early in pci_pm_suspend() and pci_pm_runtime_suspend() so we do it in all cases.
Here's a sample of errors that occur when PTM is disabled only on the Root Port. With this topology:
0000:00:1d.0 Root Port to [bus 08-71]
0000:08:00.0 Switch Upstream Port to [bus 09-71]
Kai-Heng reported errors like this:
pcieport 0000:00:1d.0: AER: Uncorrected (Non-Fatal) error received: 0000:00:1d.0
pcieport 0000:00:1d.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Requester ID)
pcieport 0000:00:1d.0: device [8086:7ab0] error status/mask=00100000/00004000
pcieport 0000:00:1d.0: [20] UnsupReq (First)
pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000
Decoding TLP header 0x34...... (0011 0100b) and 0x08000052:
Fmt 001b 4 DW header, no data Type 1 0100b Msg (Local - Terminate at Receiver) Requester ID 0x0800 Bus 08 Devfn 00.0 Message Code 0x52 0101 0010b PTM Request
The 00:1d.0 Root Port logged an Unsupported Request error when it received a PTM Request with Requester ID 08:00.0.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216210
Based-on: https://lore.kernel.org/r/[email protected]
--- drivers/pci/pci-driver.c | 8 ++++++++ drivers/pci/pci.c | 20 -------------------- 2 files changed, 8 insertions(+), 20 deletions(-)
drivers/pci/pci-driver.c +8 -0
@@ -772,6 +772,12 @@ static int pci_pm_suspend(struct device *dev)struct pci_dev *pci_dev =to_pci_dev (dev);const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm :NULL ; +/* +* Disabling PTM allows some systems, e.g., Intel mobile chips +* since Coffee Lake, to enter a lower-power PM state. +*/ +pci_disable_ptm (pci_dev); + pci_dev->skip_bus_pm = false;if (pci_has_legacy_pm_support (pci_dev))
@@ -1269,6 +1275,8 @@ static int pci_pm_runtime_suspend(struct device *dev)pci_power_t prev = pci_dev->current_state;int error; +pci_disable_ptm (pci_dev); +/* * If pci_dev->driver is not set (unbound), we leave the device in D0, * but it may go to D3cold when the bridge above it runtime suspends.
drivers/pci/pci.c +0 -20
@@ -2706,16 +2706,6 @@ int pci_prepare_to_sleep(struct pci_dev *dev)if (target_state ==PCI_POWER_ERROR )return -EIO ; -/* -* There are systems (for example, Intel mobile chips since Coffee -* Lake) where the power drawn while suspended can be significantly -* reduced by disabling PTM on PCIe root ports as this allows the -* port to enter a lower-power PM state and the SoC to reach a -* lower-power idle state as a whole. -*/ -if (pci_pcie_type (dev) ==PCI_EXP_TYPE_ROOT_PORT ) -pci_disable_ptm (dev); -pci_enable_wake (dev, target_state, wakeup); error =pci_set_power_state (dev, target_state);
@@ -2764,16 +2754,6 @@ int pci_finish_runtime_suspend(struct pci_dev *dev)if (target_state ==PCI_POWER_ERROR )return -EIO ; -/* -* There are systems (for example, Intel mobile chips since Coffee -* Lake) where the power drawn while suspended can be significantly -* reduced by disabling PTM on PCIe root ports as this allows the -* port to enter a lower-power PM state and the SoC to reach a -* lower-power idle state as a whole. -*/ -if (pci_pcie_type (dev) ==PCI_EXP_TYPE_ROOT_PORT ) -pci_disable_ptm (dev); -__pci_enable_wake (dev, target_state,pci_dev_run_wake (dev)); error =pci_set_power_state (dev, target_state);
Signature · 1 line
2.25.1
PATCH 4/4 PCI/PTM: Cache PTM Capability offset
In reply to Bjorn HelgaasFrom: Bjorn Helgaas <[email protected]>
Cache the PTM Capability offset in struct pci_dev so we don't have to search for it every time we enable/disable/save/restore. No functional change intended.
--- drivers/pci/pcie/ptm.c | 46 ++++++++++++++++-------------------------- include/linux/pci.h | 1 + 2 files changed, 18 insertions(+), 29 deletions(-)
drivers/pci/pcie/ptm.c +17 -29
@@ -31,14 +31,10 @@ static void pci_ptm_info(struct pci_dev *dev)void pci_disable_ptm (struct pci_dev *dev) { -int ptm; +u16 ptm = dev->ptm_cap;u16 ctrl; -if (!pci_is_pcie (dev)) -return ; - - ptm =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_PTM ); -if (!ptm) +if (!ptm || !dev->ptm_enabled)return ;pci_read_config_word (dev, ptm +PCI_PTM_CTRL , &ctrl);
@@ -48,14 +44,10 @@ void pci_disable_ptm(struct pci_dev *dev)void pci_save_ptm_state (struct pci_dev *dev) { -int ptm; +u16 ptm = dev->ptm_cap;struct pci_cap_saved_state *save_state;u16 *cap; -if (!pci_is_pcie (dev)) -return ; - - ptm =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_PTM );if (!ptm)return ;
@@ -69,16 +61,15 @@ void pci_save_ptm_state(struct pci_dev *dev)void pci_restore_ptm_state (struct pci_dev *dev) { +u16 ptm = dev->ptm_cap;struct pci_cap_saved_state *save_state; -int ptm;u16 *cap; -if (!pci_is_pcie (dev)) +if (!ptm)return ; save_state =pci_find_saved_ext_cap (dev,PCI_EXT_CAP_ID_PTM ); - ptm =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_PTM ); -if (!save_state || !ptm) +if (!save_state)return ; cap = (u16 *)&save_state->cap.data[0 ];
@@ -95,10 +86,10 @@ void pci_restore_ptm_state(struct pci_dev *dev)void pci_ptm_init (struct pci_dev *dev) { -int pos; +struct pci_dev *ups; +u16 ptm;u32 cap, ctrl;u8 local_clock; -struct pci_dev *ups;if (!pci_is_pcie (dev))return ;
@@ -125,13 +116,14 @@ void pci_ptm_init(struct pci_dev *dev)return ; } - pos =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_PTM ); -if (!pos) + ptm =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_PTM ); + dev->ptm_cap = ptm; +if (!ptm)return ;pci_add_ext_cap_save_buffer (dev,PCI_EXT_CAP_ID_PTM ,sizeof (u16)); -pci_read_config_dword (dev, pos +PCI_PTM_CAP , &cap); +pci_read_config_dword (dev, ptm +PCI_PTM_CAP , &cap); local_clock = (cap &PCI_PTM_GRANULARITY_MASK ) >>8 ;/*
@@ -156,7 +148,7 @@ void pci_ptm_init(struct pci_dev *dev) } ctrl |= dev->ptm_granularity <<8 ; -pci_write_config_dword (dev, pos +PCI_PTM_CTRL , ctrl); +pci_write_config_dword (dev, ptm +PCI_PTM_CTRL , ctrl); dev->ptm_enabled =1 ;pci_ptm_info (dev);
@@ -164,18 +156,14 @@ void pci_ptm_init(struct pci_dev *dev)int pci_enable_ptm (struct pci_dev *dev,u8 *granularity) { -int pos; +u16 ptm = dev->ptm_cap;u32 cap, ctrl;struct pci_dev *ups; -if (!pci_is_pcie (dev)) +if (!ptm)return -EINVAL ; - pos =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_PTM ); -if (!pos) -return -EINVAL ; - -pci_read_config_dword (dev, pos +PCI_PTM_CAP , &cap); +pci_read_config_dword (dev, ptm +PCI_PTM_CAP , &cap);if (!(cap &PCI_PTM_CAP_REQ ))return -EINVAL ;
@@ -200,7 +188,7 @@ int pci_enable_ptm(struct pci_dev *dev, u8 *granularity) ctrl =PCI_PTM_CTRL_ENABLE ; ctrl |= dev->ptm_granularity <<8 ; -pci_write_config_dword (dev, pos +PCI_PTM_CTRL , ctrl); +pci_write_config_dword (dev, ptm +PCI_PTM_CTRL , ctrl); dev->ptm_enabled =1 ;pci_ptm_info (dev);
include/linux/pci.h +1 -0
@@ -475,6 +475,7 @@ struct pci_dev { unsigned int broken_cmd_compl:1; /* No compl for some cmds */#endif #ifdef CONFIG_PCIE_PTM +u16 ptm_cap;/* PTM Capability offset */ unsigned int ptm_root:1; unsigned int ptm_enabled:1;u8 ptm_granularity;
Signature · 1 line
2.25.1