| Message ID | 1483425255-101923-6-git-send-email-rajatja@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Hi! On 03/01/17 06:34, Rajat Jain wrote: > Add code to actually configure the L1 substate settigns on the > upstream and downstream device, while taking care of the rules > dictated by the PCIe spec. While testing hibernate on an arm64 juno with v4.11-rc1, I get a NULL pointer dereference from pcie_config_aspm_link(): > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > index a70afdf..6735f38 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -597,11 +683,23 @@ static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) > static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) > { > u32 upstream = 0, dwstream = 0; > - struct pci_dev *child, *parent = link->pdev; > + struct pci_dev *child = link->downstream, *parent = link->pdev; Here link->downstream is NULL, > struct pci_bus *linkbus = parent->subordinate; > > - /* Nothing to do if the link is already in the requested state */ > + /* Enable only the states that were not explicitly disabled */ > state &= (link->aspm_capable & ~link->aspm_disable); > + > + /* Can't enable any substates if L1 is not enabled */ > + if (!(state & ASPM_STATE_L1)) > + state &= ~ASPM_STATE_L1SS; > + > + /* Spec says both ports must be in D0 before enabling PCI PM substates*/ > + if (parent->current_state != PCI_D0 || child->current_state != PCI_D0) { Which causes a crash[0] here. > + state &= ~ASPM_STATE_L1_SS_PCIPM; > + state |= (link->aspm_enabled & ASPM_STATE_L1_SS_PCIPM); > + } > + > + /* Nothing to do if the link is already in the requested state */ > if (link->aspm_enabled == state) > return; > /* Convert ASPM state to upstream/downstream ASPM register state */ (For trees based on v4.10-rc1 I need to cherry-pick b4b8664d291a to make arm64 build) Testing either side of aeda9adebab8 gives this patch as the first to expose the problem. At boot I get the message: > pci 0000:03:00.0: disabling ASPM on pre-1.1 PCIe device. You can enable it with 'pcie_aspm=force' for the pcie device being resumed here, should this code be called at all for this device? The 'pci' section of the boot log for v4.11-rc1 is below[1], and lspci[2]. Thanks, James [0] git checkout aeda9adebab8; git cherry-pick b4b8664d291a [ 170.379816] PM: noirq thaw of devices complete after 0.702 msecs [ 170.387234] PM: early thaw of devices complete after 1.390 msecs [ 170.421447] Unable to handle kernel NULL pointer dereference at virtual addre ss 00000080 [ 170.429497] pgd = ffff000008f10000 [ 170.432878] [00000080] *pgd=00000009ffffe003 [ 170.432882] , *pud=00000009ffffd003 [ 170.437118] , *pmd=0000000000000000 [ 170.440579] [ 170.445513] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 170.451027] Modules linked in: [ 170.454055] CPU: 4 PID: 2509 Comm: kworker/u12:9 Not tainted 4.10.0-rc1-00006 -g51e9dca242d2 #7202 [ 170.462837] Hardware name: ARM Juno development board (r1) (DT) [ 170.468707] Workqueue: events_unbound async_run_entry_fn [ 170.473965] task: ffff8009764c2580 task.stack: ffff80097374c000 [ 170.479831] PC is at pcie_config_aspm_link+0x4c/0x300 [ 170.484833] LR is at pcie_config_aspm_path+0x40/0x88 [ 170.489747] pc : [<ffff000008411ebc>] lr : [<ffff0000084121b0>] pstate: 40000 045 [ 170.497066] sp : ffff80097374fb40 [ 170.500343] x29: ffff80097374fb40 x28: ffff800976c0c2a8 [ 170.505603] x27: ffff800976c0c078 x26: ffff800976c0c020 [ 170.510863] x25: 0000000000000001 x24: ffff8009750f9120 [ 170.516122] x23: ffff8009764bd100 x22: ffff000008045000 [ 170.521381] x21: ffff800976c24000 x20: ffff000008ef3320 [ 170.526640] x19: 0000000000000000 x18: 0000000000000000 [ 170.531899] x17: 0000000000000000 x16: 0000000000000000 [ 170.537158] x15: 0000000000000000 x14: 00000000000000dc [ 170.542417] x13: ffff000008e17628 x12: ffff800976fa8028 [ 170.547676] x11: ffff80097641f000 x10: ffff000008e17608 [ 170.552936] x9 : ffff800976fa8028 x8 : 0000000000000000 [ 170.558194] x7 : 000000000000007b x6 : 0000000000000000 [ 170.563453] x5 : 0000000000000fa0 x4 : ffff80097641fd60 [ 170.568712] x3 : 0000000000000000 x2 : 0000000000000000 [ 170.573971] x1 : 0000000000000000 x0 : ffff80097641fd00 [ 170.579229] [ 170.580701] Process kworker/u12:9 (pid: 2509, stack limit = 0xffff80097374c00 0) [ 170.587936] Stack: (0xffff80097374fb40 to 0xffff800973750000) [ 170.888248] Call trace: [ 170.974579] [<ffff000008411ebc>] pcie_config_aspm_link+0x4c/0x300 [ 170.980614] [<ffff0000084121b0>] pcie_config_aspm_path+0x40/0x88 [ 170.986564] [<ffff0000084130f4>] pcie_aspm_pm_state_change+0x5c/0x80 [ 170.992856] [<ffff0000083ff0a4>] pci_raw_set_power_state+0x15c/0x230 [ 170.999148] [<ffff0000084018ec>] pci_set_power_state+0x64/0x150 [ 171.005013] [<ffff00000859ae20>] ata_pci_device_do_resume+0x18/0x70 [ 171.011220] [<ffff0000085baa3c>] sil24_pci_device_resume+0x24/0x78 [ 171.017341] [<ffff000008404fd8>] pci_legacy_resume+0x38/0x58 [ 171.022945] [<ffff000008405f00>] pci_pm_thaw+0xa0/0xd0 [ 171.028034] [<ffff000008546ce4>] dpm_run_callback.isra.4+0x1c/0x70 [ 171.034154] [<ffff0000085470a0>] device_resume+0x88/0x150 [ 171.039500] [<ffff00000854718c>] async_resume+0x24/0x58 [ 171.044674] [<ffff0000080de55c>] async_run_entry_fn+0x3c/0xf8 [ 171.050365] [<ffff0000080d4de8>] process_one_work+0x1d0/0x390 [ 171.056055] [<ffff0000080d4ff0>] worker_thread+0x48/0x480 [ 171.061400] [<ffff0000080daec0>] kthread+0xf8/0x128 [ 171.066230] [<ffff0000080836c0>] ret_from_fork+0x10/0x50 [ 171.071490] Code: 12196e61 f27e027f 1a930033 35000063 (b9408101) [ 171.077566] ---[ end trace 93b51adc52c63085 ]--- [1] v4.11-rc1 pci boot messages [ 0.732114] OF: PCI: host bridge /pcie-controller@30000000 ranges: [ 0.732133] OF: PCI: IO 0x5f800000..0x5fffffff -> 0x5f800000 [ 0.732145] OF: PCI: MEM 0x50000000..0x57ffffff -> 0x50000000 [ 0.732152] OF: PCI: MEM 0x4000000000..0x40ffffffff -> 0x4000000000 [ 0.732204] pci-host-generic 40000000.pcie-controller: ECAM at [mem 0x4000000 0-0x4fffffff] for [bus 00-ff] [ 0.732401] pci-host-generic 40000000.pcie-controller: PCI host bridge to bus 0000:00 [ 0.732410] pci_bus 0000:00: root bus resource [bus 00-ff] [ 0.732421] pci_bus 0000:00: root bus resource [io 0x0000-0x7fffff] (bus add ress [0x5f800000-0x5fffffff]) [ 0.732428] pci_bus 0000:00: root bus resource [mem 0x50000000-0x57ffffff] [ 0.732435] pci_bus 0000:00: root bus resource [mem 0x4000000000-0x40ffffffff pref] [ 0.732462] pci 0000:00:00.0: [1556:1100] type 01 class 0x060400 [ 0.732485] pci 0000:00:00.0: reg 0x10: [mem 0x57d00000-0x57d03fff 64bit pref] [ 0.732543] pci 0000:00:00.0: supports D1 D2 [ 0.732832] pci 0000:00:00.0: PME# supported from D0 D1 D2 D3hot D3cold [ 0.733252] pci 0000:01:00.0: [111d:8090] type 01 class 0x060400 [ 0.733423] pci 0000:01:00.0: PME# supported from D0 D3hot D3cold [ 0.744804] pci 0000:02:01.0: [111d:8090] type 01 class 0x060400 [ 0.744993] pci 0000:02:01.0: PME# supported from D0 D3hot D3cold [ 0.745223] pci 0000:02:02.0: [111d:8090] type 01 class 0x060400 [ 0.745414] pci 0000:02:02.0: PME# supported from D0 D3hot D3cold [ 0.745641] pci 0000:02:03.0: [111d:8090] type 01 class 0x060400 [ 0.745828] pci 0000:02:03.0: PME# supported from D0 D3hot D3cold [ 0.746076] pci 0000:02:0c.0: [111d:8090] type 01 class 0x060400 [ 0.746263] pci 0000:02:0c.0: PME# supported from D0 D3hot D3cold [ 0.746482] pci 0000:02:10.0: [111d:8090] type 01 class 0x060400 [ 0.746646] pci 0000:02:10.0: PME# supported from D0 D3hot D3cold [ 0.746886] pci 0000:02:1f.0: [111d:8090] type 01 class 0x060400 [ 0.747074] pci 0000:02:1f.0: PME# supported from D0 D3hot D3cold [ 0.747490] pci 0000:03:00.0: [1095:3132] type 00 class 0x018000 [ 0.747531] pci 0000:03:00.0: reg 0x10: [mem 0x57f04000-0x57f0407f 64bit] [ 0.747559] pci 0000:03:00.0: reg 0x18: [mem 0x57f00000-0x57f03fff 64bit] [ 0.747577] pci 0000:03:00.0: reg 0x20: initial BAR value 0x00000000 invalid [ 0.747584] pci 0000:03:00.0: reg 0x20: [io size 0x0080] [ 0.747614] pci 0000:03:00.0: reg 0x30: [mem 0xfff80000-0xffffffff pref] [ 0.747720] pci 0000:03:00.0: supports D1 D2 [ 0.747886] pci 0000:03:00.0: disabling ASPM on pre-1.1 PCIe device. You can enable it with 'pcie_aspm=force' [ 0.747910] pci_bus 0000:03: busn_res: [bus 03-ff] end is updated to 03 [ 0.748044] pci_bus 0000:04: busn_res: [bus 04-ff] end is updated to 04 [ 0.748180] pci_bus 0000:05: busn_res: [bus 05-ff] end is updated to 05 [ 0.748311] pci_bus 0000:06: busn_res: [bus 06-ff] end is updated to 06 [ 0.748441] pci_bus 0000:07: busn_res: [bus 07-ff] end is updated to 07 [ 0.748614] pci 0000:08:00.0: [11ab:4380] type 00 class 0x020000 [ 0.748651] pci 0000:08:00.0: reg 0x10: [mem 0x57e00000-0x57e03fff 64bit] [ 0.748668] pci 0000:08:00.0: reg 0x18: initial BAR value 0x00000000 invalid [ 0.748675] pci 0000:08:00.0: reg 0x18: [io size 0x0100] [ 0.748814] pci 0000:08:00.0: supports D1 D2 [ 0.748821] pci 0000:08:00.0: PME# supported from D0 D1 D2 D3hot D3cold [ 0.749085] pci_bus 0000:08: busn_res: [bus 08-ff] end is updated to 08 [ 0.749099] pci_bus 0000:02: busn_res: [bus 02-ff] end is updated to 08 [ 0.749112] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 08 [ 0.749249] pci 0000:00:00.0: BAR 14: assigned [mem 0x50000000-0x501fffff] [ 0.749260] pci 0000:00:00.0: BAR 0: assigned [mem 0x4000000000-0x4000003fff 64bit pref] [ 0.749272] pci 0000:00:00.0: BAR 13: assigned [io 0x1000-0x2fff] [ 0.749283] pci 0000:01:00.0: BAR 14: assigned [mem 0x50000000-0x501fffff] [ 0.749290] pci 0000:01:00.0: BAR 13: assigned [io 0x1000-0x2fff] [ 0.749303] pci 0000:02:01.0: BAR 14: assigned [mem 0x50000000-0x500fffff] [ 0.749311] pci 0000:02:1f.0: BAR 14: assigned [mem 0x50100000-0x501fffff] [ 0.749318] pci 0000:02:01.0: BAR 13: assigned [io 0x1000-0x1fff] [ 0.749325] pci 0000:02:1f.0: BAR 13: assigned [io 0x2000-0x2fff] [ 0.749337] pci 0000:03:00.0: BAR 6: assigned [mem 0x50000000-0x5007ffff pref] [ 0.749347] pci 0000:03:00.0: BAR 2: assigned [mem 0x50080000-0x50083fff 64bit] [ 0.749372] pci 0000:03:00.0: BAR 0: assigned [mem 0x50084000-0x5008407f 64bit] [ 0.749394] pci 0000:03:00.0: BAR 4: assigned [io 0x1000-0x107f] [ 0.749407] pci 0000:02:01.0: PCI bridge to [bus 03] [ 0.749416] pci 0000:02:01.0: bridge window [io 0x1000-0x1fff] [ 0.749429] pci 0000:02:01.0: bridge window [mem 0x50000000-0x500fffff] [ 0.749451] pci 0000:02:02.0: PCI bridge to [bus 04] [ 0.749479] pci 0000:02:03.0: PCI bridge to [bus 05] [ 0.749507] pci 0000:02:0c.0: PCI bridge to [bus 06] [ 0.749535] pci 0000:02:10.0: PCI bridge to [bus 07] [ 0.749569] pci 0000:08:00.0: BAR 0: assigned [mem 0x50100000-0x50103fff 64bit] [ 0.749590] pci 0000:08:00.0: BAR 2: assigned [io 0x2000-0x20ff] [ 0.749600] pci 0000:02:1f.0: PCI bridge to [bus 08] [ 0.749608] pci 0000:02:1f.0: bridge window [io 0x2000-0x2fff] [ 0.749622] pci 0000:02:1f.0: bridge window [mem 0x50100000-0x501fffff] [ 0.749643] pci 0000:01:00.0: PCI bridge to [bus 02-08] [ 0.749651] pci 0000:01:00.0: bridge window [io 0x1000-0x2fff] [ 0.749664] pci 0000:01:00.0: bridge window [mem 0x50000000-0x501fffff] [ 0.749685] pci 0000:00:00.0: PCI bridge to [bus 01-08] [ 0.749691] pci 0000:00:00.0: bridge window [io 0x1000-0x2fff] [ 0.749699] pci 0000:00:00.0: bridge window [mem 0x50000000-0x501fffff] [ 0.750009] pcieport 0000:00:00.0: Signaling PME with IRQ 39 [ 0.750155] pcieport 0000:00:00.0: AER enabled with IRQ 39 [2] lspci root@juno-r1:~# lspci 00:00.0 PCI bridge: PLDA PCI Express Core Reference Design (rev 01) 01:00.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 02:01.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 02:02.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 02:03.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 02:0c.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 02:10.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 02:1f.0 PCI bridge: Integrated Device Technology, Inc. [IDT] Device 8090 (rev 02 ) 03:00.0 Mass storage controller: Silicon Image, Inc. SiI 3132 Serial ATA Raid II Controller (rev 01) 08:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8057 PCI-E Gigabit Ethernet Controller
Hi James, On Wed, Mar 08, 2017 at 06:44:36PM +0000, James Morse wrote: > Hi! > > On 03/01/17 06:34, Rajat Jain wrote: > > Add code to actually configure the L1 substate settigns on the > > upstream and downstream device, while taking care of the rules > > dictated by the PCIe spec. > > While testing hibernate on an arm64 juno with v4.11-rc1, I get a NULL pointer > dereference from pcie_config_aspm_link(): > > > > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > > index a70afdf..6735f38 100644 > > --- a/drivers/pci/pcie/aspm.c > > +++ b/drivers/pci/pcie/aspm.c > > @@ -597,11 +683,23 @@ static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) > > static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) > > { > > u32 upstream = 0, dwstream = 0; > > - struct pci_dev *child, *parent = link->pdev; > > + struct pci_dev *child = link->downstream, *parent = link->pdev; > > > Here link->downstream is NULL, Sorry about the breakage. Can you try also cherry-picking this commit: https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/commit/?h=for-linus&id=3bd7db63a841e8c5297bb18ad801df67d5e38ad2 Yinghai tripped over a similar problem in a different way, but I suspect his fix might also fix the problem you're seeing. If that doesn't fix it, we'll have to look farther. I'm planning to ask Linus to pull this fix for v4.11-rc2. Bjorn
Hi guys, On 08/03/17 23:08, Rajat Jain wrote: > On Wed, Mar 8, 2017 at 2:39 PM, Bjorn Helgaas <helgaas@kernel.org> wrote: >> On Wed, Mar 08, 2017 at 06:44:36PM +0000, James Morse wrote: >>> On 03/01/17 06:34, Rajat Jain wrote: >>>> Add code to actually configure the L1 substate settigns on the >>>> upstream and downstream device, while taking care of the rules >>>> dictated by the PCIe spec. >>> >>> While testing hibernate on an arm64 juno with v4.11-rc1, I get a NULL >> pointer >>> dereference from pcie_config_aspm_link(): >>> >>> >>>> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c >>>> index a70afdf..6735f38 100644 >>>> --- a/drivers/pci/pcie/aspm.c >>>> +++ b/drivers/pci/pcie/aspm.c >>>> @@ -597,11 +683,23 @@ static void pcie_config_aspm_dev(struct pci_dev >> *pdev, u32 val) >>>> static void pcie_config_aspm_link(struct pcie_link_state *link, u32 >> state) >>>> { >>>> u32 upstream = 0, dwstream = 0; >>>> - struct pci_dev *child, *parent = link->pdev; >>>> + struct pci_dev *child = link->downstream, *parent = link->pdev; >>> >>> >>> Here link->downstream is NULL, >> >> Sorry about the breakage. Can you try also cherry-picking this >> commit: >> >> https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci. >> git/commit/?h=for-linus&id=3bd7db63a841e8c5297bb18ad801df67d5e38ad2 >> >> Yinghai tripped over a similar problem in a different way, but I >> suspect his fix might also fix the problem you're seeing. >> > > Yes, I think that should fix it. Yes, this fixes the problem. Thanks! I should have dug through the list a little more to see if there was an existing fix... Thanks, James
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index a70afdf..6735f38 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -588,6 +588,92 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) } } +static inline void pci_clear_and_set_dword(struct pci_dev *pdev, int pos, + u32 clear, u32 set) +{ + u32 val; + + pci_read_config_dword(pdev, pos, &val); + val &= ~clear; + val |= set; + pci_write_config_dword(pdev, pos, val); +} + +/* Configure the ASPM L1 substates */ +static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state) +{ + u32 val, enable_req; + struct pci_dev *child = link->downstream, *parent = link->pdev; + u32 up_cap_ptr = link->l1ss.up_cap_ptr; + u32 dw_cap_ptr = link->l1ss.dw_cap_ptr; + + enable_req = (link->aspm_enabled ^ state) & state; + + /* + * Here are the rules specified in the PCIe spec for enabling L1SS: + * - When enabling L1.x, enable bit at parent first, then at child + * - When disabling L1.x, disable bit at child first, then at parent + * - When enabling ASPM L1.x, need to disable L1 + * (at child followed by parent). + * - The ASPM/PCIPM L1.2 must be disabled while programming timin + * parameters + * + * To keep it simple, disable all L1SS bits first, and later enable + * what is needed. + */ + + /* Disable all L1 substates */ + pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1, + PCI_L1SS_CTL1_L1SS_MASK, 0); + pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1, + PCI_L1SS_CTL1_L1SS_MASK, 0); + /* + * If needed, disable L1, and it gets enabled later + * in pcie_config_aspm_link(). + */ + if (enable_req & (ASPM_STATE_L1_1 | ASPM_STATE_L1_2)) { + pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPM_L1, 0); + pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPM_L1, 0); + } + + if (enable_req & ASPM_STATE_L1_2_MASK) { + + /* Program T_pwr_on in both ports */ + pci_write_config_dword(parent, up_cap_ptr + PCI_L1SS_CTL2, + link->l1ss.ctl2); + pci_write_config_dword(child, dw_cap_ptr + PCI_L1SS_CTL2, + link->l1ss.ctl2); + + /* Program T_cmn_mode in parent */ + pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1, + 0xFF00, link->l1ss.ctl1); + + /* Program LTR L1.2 threshold in both ports */ + pci_clear_and_set_dword(parent, dw_cap_ptr + PCI_L1SS_CTL1, + 0xE3FF0000, link->l1ss.ctl1); + pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1, + 0xE3FF0000, link->l1ss.ctl1); + } + + val = 0; + if (state & ASPM_STATE_L1_1) + val |= PCI_L1SS_CTL1_ASPM_L1_1; + if (state & ASPM_STATE_L1_2) + val |= PCI_L1SS_CTL1_ASPM_L1_2; + if (state & ASPM_STATE_L1_1_PCIPM) + val |= PCI_L1SS_CTL1_PCIPM_L1_1; + if (state & ASPM_STATE_L1_2_PCIPM) + val |= PCI_L1SS_CTL1_PCIPM_L1_2; + + /* Enable what we need to enable */ + pci_clear_and_set_dword(parent, up_cap_ptr + PCI_L1SS_CTL1, + PCI_L1SS_CAP_L1_PM_SS, val); + pci_clear_and_set_dword(child, dw_cap_ptr + PCI_L1SS_CTL1, + PCI_L1SS_CAP_L1_PM_SS, val); +} + static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) { pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL, @@ -597,11 +683,23 @@ static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val) static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) { u32 upstream = 0, dwstream = 0; - struct pci_dev *child, *parent = link->pdev; + struct pci_dev *child = link->downstream, *parent = link->pdev; struct pci_bus *linkbus = parent->subordinate; - /* Nothing to do if the link is already in the requested state */ + /* Enable only the states that were not explicitly disabled */ state &= (link->aspm_capable & ~link->aspm_disable); + + /* Can't enable any substates if L1 is not enabled */ + if (!(state & ASPM_STATE_L1)) + state &= ~ASPM_STATE_L1SS; + + /* Spec says both ports must be in D0 before enabling PCI PM substates*/ + if (parent->current_state != PCI_D0 || child->current_state != PCI_D0) { + state &= ~ASPM_STATE_L1_SS_PCIPM; + state |= (link->aspm_enabled & ASPM_STATE_L1_SS_PCIPM); + } + + /* Nothing to do if the link is already in the requested state */ if (link->aspm_enabled == state) return; /* Convert ASPM state to upstream/downstream ASPM register state */ @@ -613,6 +711,10 @@ static void pcie_config_aspm_link(struct pcie_link_state *link, u32 state) upstream |= PCI_EXP_LNKCTL_ASPM_L1; dwstream |= PCI_EXP_LNKCTL_ASPM_L1; } + + if (link->aspm_capable & ASPM_STATE_L1SS) + pcie_config_aspm_l1ss(link, state); + /* * Spec 2.0 suggests all functions should be configured the * same setting for ASPM. Enabling ASPM L1 should be done in
Add code to actually configure the L1 substate settigns on the upstream and downstream device, while taking care of the rules dictated by the PCIe spec. Signed-off-by: Rajat Jain <rajatja@google.com> --- drivers/pci/pcie/aspm.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 104 insertions(+), 2 deletions(-)