* [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits @ 2014-06-17 19:27 Myron Stowe 2014-06-17 21:07 ` Bjorn Helgaas 0 siblings, 1 reply; 11+ messages in thread From: Myron Stowe @ 2014-06-17 19:27 UTC (permalink / raw) To: bhelgaas, linux-pci; +Cc: kaneshige.kenji, linux-kernel During PCIe hot-plug initialization - pciehp_probe - data structures related to slot capabilities are set up. As part of this set up, ISRs are put in place to handle slot events and all event bits are cleared out. This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) Slot Status bit to the event bits that are cleared out during initialization. Reference: PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). Signed-off-by: Myron Stowe <myron.stowe@redhat.com> --- drivers/pci/hotplug/pciehp_hpc.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 42914e0..0568416 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | - PCI_EXP_SLTSTA_CC); + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); /* Disable software notification */ pcie_disable_notification(ctrl); ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-17 19:27 [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits Myron Stowe @ 2014-06-17 21:07 ` Bjorn Helgaas 2014-06-17 22:55 ` Guenter Roeck 2014-06-30 16:49 ` Myron Stowe 0 siblings, 2 replies; 11+ messages in thread From: Bjorn Helgaas @ 2014-06-17 21:07 UTC (permalink / raw) To: Myron Stowe Cc: linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe <myron.stowe@redhat.com> wrote: > During PCIe hot-plug initialization - pciehp_probe - data structures > related to slot capabilities are set up. As part of this set up, ISRs are > put in place to handle slot events and all event bits are cleared out. > > This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) > Slot Status bit to the event bits that are cleared out during > initialization. I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change notifications for hot-plug and removal"). Prior to that, pcie_isr() didn't look at the PCI_EXP_SLTSTA_DLLSC bit. Apparently there's a non-public report of spurious messages like this at boot-time, with no actual hotplug events: pciehp 0000:82:04.0:pcie24: slot(4): Link Up event pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at 0000:83:00, cannot hot-add pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 Device 0000:83:00.0 was enumerated previously, during the normal PCI device enumeration. I suspect DLLSC was set by the hardware when the link came up after power-on, and it remained set until Linux booted. Then when we take the first pciehp interrupt, we notice DLLSC is set and think it's a new link state change. This might be system-specific, because some BIOSes might clear DLLSC before handing off to the OS. Or my theory might be all wet. But I think we should clear DLLSC in any case. We clear all the other RW1C bits in Slot Status, and I think we should clear DLLSC as well. I'd like to include a bugzilla or mailing list reference for the spurious message, and I'd also like confirmation that this changes actually fixes it. Bjorn > Reference: > PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 > (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). > > Signed-off-by: Myron Stowe <myron.stowe@redhat.com> > --- > > drivers/pci/hotplug/pciehp_hpc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c > index 42914e0..0568416 100644 > --- a/drivers/pci/hotplug/pciehp_hpc.c > +++ b/drivers/pci/hotplug/pciehp_hpc.c > @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) > pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, > PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | > PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | > - PCI_EXP_SLTSTA_CC); > + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); > > /* Disable software notification */ > pcie_disable_notification(ctrl); > ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-17 21:07 ` Bjorn Helgaas @ 2014-06-17 22:55 ` Guenter Roeck 2014-06-24 20:34 ` Rajat Jain 2014-06-30 16:49 ` Myron Stowe 1 sibling, 1 reply; 11+ messages in thread From: Guenter Roeck @ 2014-06-17 22:55 UTC (permalink / raw) To: Bjorn Helgaas, Myron Stowe Cc: linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On 06/17/2014 02:07 PM, Bjorn Helgaas wrote: > On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe <myron.stowe@redhat.com> wrote: >> During PCIe hot-plug initialization - pciehp_probe - data structures >> related to slot capabilities are set up. As part of this set up, ISRs are >> put in place to handle slot events and all event bits are cleared out. >> >> This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) >> Slot Status bit to the event bits that are cleared out during >> initialization. > > I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change > notifications for hot-plug and removal"). Prior to that, pcie_isr() > didn't look at the PCI_EXP_SLTSTA_DLLSC bit. > > Apparently there's a non-public report of spurious messages like this > at boot-time, with no actual hotplug events: > > pciehp 0000:82:04.0:pcie24: slot(4): Link Up event > pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at > 0000:83:00, cannot hot-add > pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 > I think I have seen that message once in a while in our systems. Rajat, didn't we talk about this a while ago ? Guenter > Device 0000:83:00.0 was enumerated previously, during the normal PCI > device enumeration. I suspect DLLSC was set by the hardware when the > link came up after power-on, and it remained set until Linux booted. > Then when we take the first pciehp interrupt, we notice DLLSC is set > and think it's a new link state change. > > This might be system-specific, because some BIOSes might clear DLLSC > before handing off to the OS. Or my theory might be all wet. > > But I think we should clear DLLSC in any case. We clear all the other > RW1C bits in Slot Status, and I think we should clear DLLSC as well. > > I'd like to include a bugzilla or mailing list reference for the > spurious message, and I'd also like confirmation that this changes > actually fixes it. > > Bjorn > >> Reference: >> PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 >> (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). >> >> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> >> --- >> >> drivers/pci/hotplug/pciehp_hpc.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c >> index 42914e0..0568416 100644 >> --- a/drivers/pci/hotplug/pciehp_hpc.c >> +++ b/drivers/pci/hotplug/pciehp_hpc.c >> @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) >> pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, >> PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | >> PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | >> - PCI_EXP_SLTSTA_CC); >> + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); >> >> /* Disable software notification */ >> pcie_disable_notification(ctrl); >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > > > ^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-17 22:55 ` Guenter Roeck @ 2014-06-24 20:34 ` Rajat Jain 2014-06-24 21:16 ` Bjorn Helgaas 0 siblings, 1 reply; 11+ messages in thread From: Rajat Jain @ 2014-06-24 20:34 UTC (permalink / raw) To: Guenter Roeck, Bjorn Helgaas, Myron Stowe Cc: linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain SGVsbG8sDQoNClNvcnJ5LCBJIG1pc3NlZCB0aGlzIGVtYWlsLg0KDQpQbGVhc2Ugc2VlIGJlbG93 LiANCg0KPiAtLS0tLU9yaWdpbmFsIE1lc3NhZ2UtLS0tLQ0KPiBGcm9tOiBsaW51eC1wY2ktb3du ZXJAdmdlci5rZXJuZWwub3JnIFttYWlsdG86bGludXgtcGNpLQ0KPiBvd25lckB2Z2VyLmtlcm5l bC5vcmddIE9uIEJlaGFsZiBPZiBHdWVudGVyIFJvZWNrDQo+IFNlbnQ6IFR1ZXNkYXksIEp1bmUg MTcsIDIwMTQgMzo1NiBQTQ0KPiBUbzogQmpvcm4gSGVsZ2FhczsgTXlyb24gU3Rvd2UNCj4gQ2M6 IGxpbnV4LXBjaUB2Z2VyLmtlcm5lbC5vcmc7IEtlbmppIEthbmVzaGlnZTsgbGludXgtDQo+IGtl cm5lbEB2Z2VyLmtlcm5lbC5vcmc7IFJhamF0IEphaW4NCj4gU3ViamVjdDogUmU6IFtQQVRDSF0g UENJOiBwY2llaHA6IEluY2x1ZGUgdGhlIERhdGEgTGluayBMYXllciBTdGF0ZSBDaGFuZ2VkDQo+ IGJpdCB3aGVuIGNsZWFyaW5nIHRoZSBTbG90IFN0YXR1cyByZWdpc3RlcidzIGV2ZW50IGJpdHMN Cj4gDQo+IE9uIDA2LzE3LzIwMTQgMDI6MDcgUE0sIEJqb3JuIEhlbGdhYXMgd3JvdGU6DQo+ID4g T24gVHVlLCBKdW4gMTcsIDIwMTQgYXQgMToyNyBQTSwgTXlyb24gU3Rvd2UNCj4gPG15cm9uLnN0 b3dlQHJlZGhhdC5jb20+IHdyb3RlOg0KPiA+PiBEdXJpbmcgUENJZSBob3QtcGx1ZyBpbml0aWFs aXphdGlvbiAtIHBjaWVocF9wcm9iZSAtIGRhdGEgc3RydWN0dXJlcw0KPiA+PiByZWxhdGVkIHRv IHNsb3QgY2FwYWJpbGl0aWVzIGFyZSBzZXQgdXAuICBBcyBwYXJ0IG9mIHRoaXMgc2V0IHVwLA0K PiA+PiBJU1JzIGFyZSBwdXQgaW4gcGxhY2UgdG8gaGFuZGxlIHNsb3QgZXZlbnRzIGFuZCBhbGwg ZXZlbnQgYml0cyBhcmUgY2xlYXJlZA0KPiBvdXQuDQo+ID4+DQo+ID4+IFRoaXMgcGF0Y2ggYWRk cyB0aGUgRGF0YSBMaW5rIExheWVyIFN0YXRlIENoYW5nZWQNCj4gPj4gKFBDSV9FWFBfU0xUU1RB X0RMTFNDKSBTbG90IFN0YXR1cyBiaXQgdG8gdGhlIGV2ZW50IGJpdHMgdGhhdCBhcmUNCj4gPj4g Y2xlYXJlZCBvdXQgZHVyaW5nIGluaXRpYWxpemF0aW9uLg0KPiA+DQo+ID4gSSB0aGluayB0aGlz IGlzIHJlbGF0ZWQgdG8gZTQ4ZjFiNjdmNjY4ICgiUENJOiBwY2llaHA6IFVzZSBsaW5rIGNoYW5n ZQ0KPiA+IG5vdGlmaWNhdGlvbnMgZm9yIGhvdC1wbHVnIGFuZCByZW1vdmFsIikuICBQcmlvciB0 byB0aGF0LCBwY2llX2lzcigpDQo+ID4gZGlkbid0IGxvb2sgYXQgdGhlIFBDSV9FWFBfU0xUU1RB X0RMTFNDIGJpdC4NCj4gPg0KPiA+IEFwcGFyZW50bHkgdGhlcmUncyBhIG5vbi1wdWJsaWMgcmVw b3J0IG9mIHNwdXJpb3VzIG1lc3NhZ2VzIGxpa2UgdGhpcw0KPiA+IGF0IGJvb3QtdGltZSwgd2l0 aCBubyBhY3R1YWwgaG90cGx1ZyBldmVudHM6DQo+ID4NCj4gPiAgICBwY2llaHAgMDAwMDo4Mjow NC4wOnBjaWUyNDogc2xvdCg0KTogTGluayBVcCBldmVudA0KPiA+ICAgIHBjaWVocCAwMDAwOjgy OjA0LjA6cGNpZTI0OiBEZXZpY2UgMDAwMDo4MzowMC4wIGFscmVhZHkgZXhpc3RzIGF0DQo+ID4g MDAwMDo4MzowMCwgY2Fubm90IGhvdC1hZGQNCj4gPiAgICBwY2llaHAgMDAwMDo4MjowNC4wOnBj aWUyNDogQ2Fubm90IGFkZCBkZXZpY2UgYXQgMDAwMDo4MzowMA0KPiA+DQo+IA0KPiBJIHRoaW5r IEkgaGF2ZSBzZWVuIHRoYXQgbWVzc2FnZSBvbmNlIGluIGEgd2hpbGUgaW4gb3VyIHN5c3RlbXMu DQo+IFJhamF0LCBkaWRuJ3Qgd2UgdGFsayBhYm91dCB0aGlzIGEgd2hpbGUgYWdvID8NCg0KRXNz ZW50aWFsbHkgbXkgaGljY3VwIHdhcyB0aGF0IEkgd2FzIG5vdCBzdXJlIHdoZXRoZXIgdGhlIGRy aXZlciBzaG91bGQgb3Igc2hvdWxkIG5vdCB0YWtlIGNhcmUgb2YgdGhlIGxpbmsgY2hhbmdlIGV2 ZW50cyB0aGF0IGhhdmUgaGFwcGVuZWQgQkVGT1JFIHRoZSBkcml2ZXIgZ2V0cyBsb2FkZWQuIFRo aXMgaGFzIG1vcmUgaW1wYWN0IGlmIHRoZSBwY2llaHAgaXMgYnVpbHQgYXMgYSBrZXJuZWwgbW9k dWxlLg0KDQpBcyBhbiBleGFtcGxlOg0KDQpJdCBpcyBjb21tb24gZm9yIHRoZSBwbGF0Zm9ybSBp bml0IGNvZGUgYnVpbHQgaW50byB0aGUga2VybmVsLCB0byB0YWtlIHRoZSBQQ0kgZGV2aWNlcyBv biB0aGUgYm9hcmQgb3V0IG9mIHJlc2V0LiBBbmQgdGhhdCBjYW4gaGFwcGVuIGFmdGVyIHRoZSBQ Q0kgZW51bWVyYXRpb24gYnV0IGJlZm9yZSB0aGUgcGNpZWhwIGRyaXZlciBnZXRzIGxvYWRlZC4g VGh1cyBpbiB0aGlzIGNvbmRpdGlvbiwgd2l0aCB0aGlzIHBhdGNoLCB0aGUgcGNpZWhwIHdpbGwg aWdub3JlIHRoZSBsaW5rdXAgZXZlbnQsIHRodXMgZGV2aWNlIHdpbGwgbm90IGJlIHZpc2libGUu IFRoZSBvbmx5IHdheSAob3RoZXIgdGhhbiBhIHJlc2NhbikgdG8gZG8gaG90LWFkZCB0aGUgZGV2 aWNlIHdvdWxkIGJlIHRvIGFwcGx5LWFuZC1yZW1vdmUtcmVzZXQtc2lnbmFsIHRvIHRoZSBkZXZp Y2UgYWdhaW4uIEF0IHdoaWNoIHBvaW50IHBjaWVocCBtYXkgZ2l2ZSBhIHdhcm5pbmcgYWJvdXQg YWJvdXQgYW4gYXR0ZW1wdCB0byByZW1vdmUgYSBub24tZXhpc3RlbnQgY2FyZCwgYW5kIHRoZW4g d2lsbCBwcm9jZWVkIGZpbmUgd2l0aCBob3QtYWRkLg0KDQpUaGUgcGF0Y2ggbG9va3MgZ29vZCwg b25seSB3YW50ZWQgdG8gbWFrZSBzdXJlIHRoYXQgd2UgdW5kZXJzdGFuZCBhbmQgYWdyZWUgdGhh dCB0aGUgcGNpZWhwIHNob3VsZCBOT1QgcHJvY2VzcyBhbmQgbGluayBldmVudHMgdGhhdCBoYXZl IGhhcHBlbmVkIGJlZm9yZSB0aGUgcGNpZWhwIHdhcyBsb2FkZWQuDQoNCkFja2VkLWJ5OiBSYWph dCBKYWluIDxyYWphdGphaW5AanVuaXBlci5uZXQ+DQoNClRoYW5rcywNCg0KUmFqYXQNCg0KDQo= ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-24 20:34 ` Rajat Jain @ 2014-06-24 21:16 ` Bjorn Helgaas 2014-06-25 5:26 ` Rajat Jain 0 siblings, 1 reply; 11+ messages in thread From: Bjorn Helgaas @ 2014-06-24 21:16 UTC (permalink / raw) To: Rajat Jain Cc: Guenter Roeck, Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Tue, Jun 24, 2014 at 2:34 PM, Rajat Jain <rajatjain@juniper.net> wrote: > Hello, > > Sorry, I missed this email. > > Please see below. > >> -----Original Message----- >> From: linux-pci-owner@vger.kernel.org [mailto:linux-pci- >> owner@vger.kernel.org] On Behalf Of Guenter Roeck >> Sent: Tuesday, June 17, 2014 3:56 PM >> To: Bjorn Helgaas; Myron Stowe >> Cc: linux-pci@vger.kernel.org; Kenji Kaneshige; linux- >> kernel@vger.kernel.org; Rajat Jain >> Subject: Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed >> bit when clearing the Slot Status register's event bits >> >> On 06/17/2014 02:07 PM, Bjorn Helgaas wrote: >> > On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe >> <myron.stowe@redhat.com> wrote: >> >> During PCIe hot-plug initialization - pciehp_probe - data structures >> >> related to slot capabilities are set up. As part of this set up, >> >> ISRs are put in place to handle slot events and all event bits are cleared >> out. >> >> >> >> This patch adds the Data Link Layer State Changed >> >> (PCI_EXP_SLTSTA_DLLSC) Slot Status bit to the event bits that are >> >> cleared out during initialization. >> > >> > I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change >> > notifications for hot-plug and removal"). Prior to that, pcie_isr() >> > didn't look at the PCI_EXP_SLTSTA_DLLSC bit. >> > >> > Apparently there's a non-public report of spurious messages like this >> > at boot-time, with no actual hotplug events: >> > >> > pciehp 0000:82:04.0:pcie24: slot(4): Link Up event >> > pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at >> > 0000:83:00, cannot hot-add >> > pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 >> > >> >> I think I have seen that message once in a while in our systems. >> Rajat, didn't we talk about this a while ago ? > > Essentially my hiccup was that I was not sure whether the driver should or should not take care of the link change events that have happened BEFORE the driver gets loaded. This has more impact if the pciehp is built as a kernel module. > > As an example: > > It is common for the platform init code built into the kernel, to take the PCI devices on the board out of reset. And that can happen after the PCI enumeration but before the pciehp driver gets loaded. Thus in this condition, with this patch, the pciehp will ignore the linkup event, thus device will not be visible. The only way (other than a rescan) to do hot-add the device would be to apply-and-remove-reset-signal to the device again. At which point pciehp may give a warning about about an attempt to remove a non-existent card, and then will proceed fine with hot-add. When you saw these problems, was pciehp a module? We changed it (c10cc483bf3f in v3.11) so it can't be a module any more, but if there can still be a significant window between enumeration and pciehp init, I'd like to understand more about it. > The patch looks good, only wanted to make sure that we understand and agree that the pciehp should NOT process and link events that have happened before the pciehp was loaded. Currently (before this patch), we clear the Attention Button Pressed, Power Fault Detected, MRL Sensor Changed, Presence Detect Changed, and Command Completed bits, but we *don't* clear Data Link Layer State Changed. That asymmetry seems hard to justify. For example, if a card were inserted after enumeration but before pciehp is initialized, we'd miss the PDC indication, so I think we would fail to notice the new device. That seems basically the same as missing the linkup event in your example. In both cases, I think we *should* notice the new device, so the fact that we don't is a problem. But since pciehp can't be a module any more, the window between PCI enumeration and pciehp initialization should be relatively small. I think the best way to fix this would be to integrate pciehp more closely into PCI enumeration, e.g., by doing pcie_init() at the point where we discover the bridge, before we enumerate any devices below the bridge. This is somewhat tangled up with acpihp, so I don't know how complicated it would be to do this. So I guess my argument is: - Ignoring events that happen before pciehp init decreases our dependency on BIOS - Handling all events consistently is very important - We currently have a problem with missing pre-pciehp events, but there is a way to fix this > Acked-by: Rajat Jain <rajatjain@juniper.net> Thanks for taking a look at this! Bjorn ^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-24 21:16 ` Bjorn Helgaas @ 2014-06-25 5:26 ` Rajat Jain 2014-06-25 17:51 ` Bjorn Helgaas 0 siblings, 1 reply; 11+ messages in thread From: Rajat Jain @ 2014-06-25 5:26 UTC (permalink / raw) To: Bjorn Helgaas Cc: Guenter Roeck, Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain SGVsbG8sDQoNCj4gPj4NCj4gPj4gT24gMDYvMTcvMjAxNCAwMjowNyBQTSwgQmpvcm4gSGVsZ2Fh cyB3cm90ZToNCj4gPj4gPiBPbiBUdWUsIEp1biAxNywgMjAxNCBhdCAxOjI3IFBNLCBNeXJvbiBT dG93ZQ0KPiA+PiA8bXlyb24uc3Rvd2VAcmVkaGF0LmNvbT4gd3JvdGU6DQo+ID4+ID4+IER1cmlu ZyBQQ0llIGhvdC1wbHVnIGluaXRpYWxpemF0aW9uIC0gcGNpZWhwX3Byb2JlIC0gZGF0YQ0KPiA+ PiA+PiBzdHJ1Y3R1cmVzIHJlbGF0ZWQgdG8gc2xvdCBjYXBhYmlsaXRpZXMgYXJlIHNldCB1cC4g IEFzIHBhcnQgb2YNCj4gPj4gPj4gdGhpcyBzZXQgdXAsIElTUnMgYXJlIHB1dCBpbiBwbGFjZSB0 byBoYW5kbGUgc2xvdCBldmVudHMgYW5kIGFsbA0KPiA+PiA+PiBldmVudCBiaXRzIGFyZSBjbGVh 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* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-25 5:26 ` Rajat Jain @ 2014-06-25 17:51 ` Bjorn Helgaas 0 siblings, 0 replies; 11+ messages in thread From: Bjorn Helgaas @ 2014-06-25 17:51 UTC (permalink / raw) To: Rajat Jain Cc: Guenter Roeck, Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Tue, Jun 24, 2014 at 11:26 PM, Rajat Jain <rajatjain@juniper.net> wrote: >> > Essentially my hiccup was that I was not sure whether the driver should or >> should not take care of the link change events that have happened BEFORE >> the driver gets loaded. This has more impact if the pciehp is built as a kernel >> module. >> > >> > As an example: >> > >> > It is common for the platform init code built into the kernel, to take the PCI >> devices on the board out of reset. And that can happen after the PCI >> enumeration but before the pciehp driver gets loaded. Thus in this condition, >> with this patch, the pciehp will ignore the linkup event, thus device will not >> be visible. The only way (other than a rescan) to do hot-add the device would >> be to apply-and-remove-reset-signal to the device again. At which point >> pciehp may give a warning about about an attempt to remove a non-existent >> card, and then will proceed fine with hot-add. >> >> When you saw these problems, was pciehp a module? > > No, we did not actually hit *this* problem (DLLSC getting set before pciehp init). We had observed another HW specific problem where both link event and presence detect were toggling, hence 2 independent hot-plug interrupts events were coming, thus resulting in spurious messages. OK, this sounds like a slightly different problem that we can work on later if it turns out to be necessary. > > For example, if a card were inserted >> after enumeration but before pciehp is initialized, we'd miss the PDC >> indication, so I think we would fail to notice the new device. >> That seems basically the same as missing the linkup event in your example. >> In both cases, I think we *should* notice the new device, so the fact that we >> don't is a problem. > ... >> - We currently have a problem with missing pre-pciehp events, but there is >> a way to fix this > > Somewhat agree (I do not understand what that way is currently. But I think it can wait as we don't hit that problem today and also the window where it can occur is very small). My thought was that we could fix this by integrating pciehp into PCI enumeration, so we're prepared to handle hotplug events on the bridge before we enumerate any device below the bridge. But I haven't actually tried this so I don't know whether it's practical. Bjorn ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-17 21:07 ` Bjorn Helgaas 2014-06-17 22:55 ` Guenter Roeck @ 2014-06-30 16:49 ` Myron Stowe 2014-07-01 19:29 ` Bjorn Helgaas 1 sibling, 1 reply; 11+ messages in thread From: Myron Stowe @ 2014-06-30 16:49 UTC (permalink / raw) To: Bjorn Helgaas Cc: Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Tue, Jun 17, 2014 at 3:07 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: > On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe <myron.stowe@redhat.com> wrote: >> During PCIe hot-plug initialization - pciehp_probe - data structures >> related to slot capabilities are set up. As part of this set up, ISRs are >> put in place to handle slot events and all event bits are cleared out. >> >> This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) >> Slot Status bit to the event bits that are cleared out during >> initialization. > > I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change > notifications for hot-plug and removal"). Prior to that, pcie_isr() > didn't look at the PCI_EXP_SLTSTA_DLLSC bit. > > Apparently there's a non-public report of spurious messages like this > at boot-time, with no actual hotplug events: > > pciehp 0000:82:04.0:pcie24: slot(4): Link Up event > pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at > 0000:83:00, cannot hot-add > pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 > > Device 0000:83:00.0 was enumerated previously, during the normal PCI > device enumeration. I suspect DLLSC was set by the hardware when the > link came up after power-on, and it remained set until Linux booted. > Then when we take the first pciehp interrupt, we notice DLLSC is set > and think it's a new link state change. > > This might be system-specific, because some BIOSes might clear DLLSC > before handing off to the OS. Or my theory might be all wet. > > But I think we should clear DLLSC in any case. We clear all the other > RW1C bits in Slot Status, and I think we should clear DLLSC as well. > > I'd like to include a bugzilla or mailing list reference for the > spurious message, and I'd also like confirmation that this changes > actually fixes it. I just got confirmation from the reporter that the patch fixes the issue they were encountering. I've also asked them numerous time if I could make the bug public as I expect others may be hitting it and could benefit from a BZ and analysis/explanation. I just repeated my request - if they reply positively I'll follow through with some documentation. Myron > > Bjorn > >> Reference: >> PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 >> (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). >> >> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> >> --- >> >> drivers/pci/hotplug/pciehp_hpc.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c >> index 42914e0..0568416 100644 >> --- a/drivers/pci/hotplug/pciehp_hpc.c >> +++ b/drivers/pci/hotplug/pciehp_hpc.c >> @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) >> pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, >> PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | >> PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | >> - PCI_EXP_SLTSTA_CC); >> + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); >> >> /* Disable software notification */ >> pcie_disable_notification(ctrl); >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-06-30 16:49 ` Myron Stowe @ 2014-07-01 19:29 ` Bjorn Helgaas 2014-07-07 20:26 ` Myron Stowe 0 siblings, 1 reply; 11+ messages in thread From: Bjorn Helgaas @ 2014-07-01 19:29 UTC (permalink / raw) To: Myron Stowe Cc: Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Mon, Jun 30, 2014 at 10:49 AM, Myron Stowe <myron.stowe@gmail.com> wrote: > On Tue, Jun 17, 2014 at 3:07 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: >> On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe <myron.stowe@redhat.com> wrote: >>> During PCIe hot-plug initialization - pciehp_probe - data structures >>> related to slot capabilities are set up. As part of this set up, ISRs are >>> put in place to handle slot events and all event bits are cleared out. >>> >>> This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) >>> Slot Status bit to the event bits that are cleared out during >>> initialization. >> >> I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change >> notifications for hot-plug and removal"). Prior to that, pcie_isr() >> didn't look at the PCI_EXP_SLTSTA_DLLSC bit. >> >> Apparently there's a non-public report of spurious messages like this >> at boot-time, with no actual hotplug events: >> >> pciehp 0000:82:04.0:pcie24: slot(4): Link Up event >> pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at >> 0000:83:00, cannot hot-add >> pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 >> >> Device 0000:83:00.0 was enumerated previously, during the normal PCI >> device enumeration. I suspect DLLSC was set by the hardware when the >> link came up after power-on, and it remained set until Linux booted. >> Then when we take the first pciehp interrupt, we notice DLLSC is set >> and think it's a new link state change. >> >> This might be system-specific, because some BIOSes might clear DLLSC >> before handing off to the OS. Or my theory might be all wet. >> >> But I think we should clear DLLSC in any case. We clear all the other >> RW1C bits in Slot Status, and I think we should clear DLLSC as well. >> >> I'd like to include a bugzilla or mailing list reference for the >> spurious message, and I'd also like confirmation that this changes >> actually fixes it. > > I just got confirmation from the reporter that the patch fixes the > issue they were encountering. > > I've also asked them numerous time if I could make the bug public as I > expect others may be hitting it and could benefit from a BZ and > analysis/explanation. I just repeated my request - if they reply > positively I'll follow through with some documentation. I'd be glad to merge this, as soon as we get more details about the problem it fixes. I think it's good to include some specifics, e.g., "Unexpected Link Up event," etc., because it helps other people with the same problem to find the solution. It's OK if details about pre-production machines and so on are removed, but it's better if changes to generic code are supported by public evidence that everybody can evaluate. If you want to pull out the public stuff into a kernel.org bugzilla, that would be fine, too. That would actually be better because then we don't have to depend on Red Hat maintaining it. Bjorn >>> Reference: >>> PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 >>> (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). >>> >>> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> >>> --- >>> >>> drivers/pci/hotplug/pciehp_hpc.c | 2 +- >>> 1 files changed, 1 insertions(+), 1 deletions(-) >>> >>> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c >>> index 42914e0..0568416 100644 >>> --- a/drivers/pci/hotplug/pciehp_hpc.c >>> +++ b/drivers/pci/hotplug/pciehp_hpc.c >>> @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) >>> pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, >>> PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | >>> PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | >>> - PCI_EXP_SLTSTA_CC); >>> + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); >>> >>> /* Disable software notification */ >>> pcie_disable_notification(ctrl); >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-07-01 19:29 ` Bjorn Helgaas @ 2014-07-07 20:26 ` Myron Stowe 2014-07-07 20:56 ` Bjorn Helgaas 0 siblings, 1 reply; 11+ messages in thread From: Myron Stowe @ 2014-07-07 20:26 UTC (permalink / raw) To: Bjorn Helgaas Cc: Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Tue, Jul 1, 2014 at 1:29 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: > On Mon, Jun 30, 2014 at 10:49 AM, Myron Stowe <myron.stowe@gmail.com> wrote: >> On Tue, Jun 17, 2014 at 3:07 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: >>> On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe <myron.stowe@redhat.com> wrote: >>>> During PCIe hot-plug initialization - pciehp_probe - data structures >>>> related to slot capabilities are set up. As part of this set up, ISRs are >>>> put in place to handle slot events and all event bits are cleared out. >>>> >>>> This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) >>>> Slot Status bit to the event bits that are cleared out during >>>> initialization. >>> >>> I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change >>> notifications for hot-plug and removal"). Prior to that, pcie_isr() >>> didn't look at the PCI_EXP_SLTSTA_DLLSC bit. >>> >>> Apparently there's a non-public report of spurious messages like this >>> at boot-time, with no actual hotplug events: >>> >>> pciehp 0000:82:04.0:pcie24: slot(4): Link Up event >>> pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at >>> 0000:83:00, cannot hot-add >>> pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 >>> >>> Device 0000:83:00.0 was enumerated previously, during the normal PCI >>> device enumeration. I suspect DLLSC was set by the hardware when the >>> link came up after power-on, and it remained set until Linux booted. >>> Then when we take the first pciehp interrupt, we notice DLLSC is set >>> and think it's a new link state change. >>> >>> This might be system-specific, because some BIOSes might clear DLLSC >>> before handing off to the OS. Or my theory might be all wet. >>> >>> But I think we should clear DLLSC in any case. We clear all the other >>> RW1C bits in Slot Status, and I think we should clear DLLSC as well. >>> >>> I'd like to include a bugzilla or mailing list reference for the >>> spurious message, and I'd also like confirmation that this changes >>> actually fixes it. >> >> I just got confirmation from the reporter that the patch fixes the >> issue they were encountering. >> >> I've also asked them numerous time if I could make the bug public as I >> expect others may be hitting it and could benefit from a BZ and >> analysis/explanation. I just repeated my request - if they reply >> positively I'll follow through with some documentation. > > I'd be glad to merge this, as soon as we get more details about the > problem it fixes. I think it's good to include some specifics, e.g., > "Unexpected Link Up event," etc., because it helps other people with > the same problem to find the solution. It's OK if details about > pre-production machines and so on are removed, but it's better if > changes to generic code are supported by public evidence that > everybody can evaluate. > > If you want to pull out the public stuff into a kernel.org bugzilla, > that would be fine, too. That would actually be better because then > we don't have to depend on Red Hat maintaining it. Agreed (but I couldn't get the vendor to agree to open up the Red Hat BZ). I've opened https://bugzilla.kernel.org/show_bug.cgi?id=79611 and included a scrubbed 'dmesg' log there along with an analysis of how we are hitting the issue. > > Bjorn > >>>> Reference: >>>> PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 >>>> (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). >>>> >>>> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> >>>> --- >>>> >>>> drivers/pci/hotplug/pciehp_hpc.c | 2 +- >>>> 1 files changed, 1 insertions(+), 1 deletions(-) >>>> >>>> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c >>>> index 42914e0..0568416 100644 >>>> --- a/drivers/pci/hotplug/pciehp_hpc.c >>>> +++ b/drivers/pci/hotplug/pciehp_hpc.c >>>> @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) >>>> pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, >>>> PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | >>>> PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | >>>> - PCI_EXP_SLTSTA_CC); >>>> + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); >>>> >>>> /* Disable software notification */ >>>> pcie_disable_notification(ctrl); >>>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits 2014-07-07 20:26 ` Myron Stowe @ 2014-07-07 20:56 ` Bjorn Helgaas 0 siblings, 0 replies; 11+ messages in thread From: Bjorn Helgaas @ 2014-07-07 20:56 UTC (permalink / raw) To: Myron Stowe Cc: Myron Stowe, linux-pci@vger.kernel.org, Kenji Kaneshige, linux-kernel@vger.kernel.org, Rajat Jain On Mon, Jul 7, 2014 at 2:26 PM, Myron Stowe <myron.stowe@gmail.com> wrote: > On Tue, Jul 1, 2014 at 1:29 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: >> On Mon, Jun 30, 2014 at 10:49 AM, Myron Stowe <myron.stowe@gmail.com> wrote: >>> On Tue, Jun 17, 2014 at 3:07 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: >>>> On Tue, Jun 17, 2014 at 1:27 PM, Myron Stowe <myron.stowe@redhat.com> wrote: >>>>> During PCIe hot-plug initialization - pciehp_probe - data structures >>>>> related to slot capabilities are set up. As part of this set up, ISRs are >>>>> put in place to handle slot events and all event bits are cleared out. >>>>> >>>>> This patch adds the Data Link Layer State Changed (PCI_EXP_SLTSTA_DLLSC) >>>>> Slot Status bit to the event bits that are cleared out during >>>>> initialization. >>>> >>>> I think this is related to e48f1b67f668 ("PCI: pciehp: Use link change >>>> notifications for hot-plug and removal"). Prior to that, pcie_isr() >>>> didn't look at the PCI_EXP_SLTSTA_DLLSC bit. >>>> >>>> Apparently there's a non-public report of spurious messages like this >>>> at boot-time, with no actual hotplug events: >>>> >>>> pciehp 0000:82:04.0:pcie24: slot(4): Link Up event >>>> pciehp 0000:82:04.0:pcie24: Device 0000:83:00.0 already exists at >>>> 0000:83:00, cannot hot-add >>>> pciehp 0000:82:04.0:pcie24: Cannot add device at 0000:83:00 >>>> >>>> Device 0000:83:00.0 was enumerated previously, during the normal PCI >>>> device enumeration. I suspect DLLSC was set by the hardware when the >>>> link came up after power-on, and it remained set until Linux booted. >>>> Then when we take the first pciehp interrupt, we notice DLLSC is set >>>> and think it's a new link state change. >>>> >>>> This might be system-specific, because some BIOSes might clear DLLSC >>>> before handing off to the OS. Or my theory might be all wet. >>>> >>>> But I think we should clear DLLSC in any case. We clear all the other >>>> RW1C bits in Slot Status, and I think we should clear DLLSC as well. >>>> >>>> I'd like to include a bugzilla or mailing list reference for the >>>> spurious message, and I'd also like confirmation that this changes >>>> actually fixes it. >>> >>> I just got confirmation from the reporter that the patch fixes the >>> issue they were encountering. >>> >>> I've also asked them numerous time if I could make the bug public as I >>> expect others may be hitting it and could benefit from a BZ and >>> analysis/explanation. I just repeated my request - if they reply >>> positively I'll follow through with some documentation. >> >> I'd be glad to merge this, as soon as we get more details about the >> problem it fixes. I think it's good to include some specifics, e.g., >> "Unexpected Link Up event," etc., because it helps other people with >> the same problem to find the solution. It's OK if details about >> pre-production machines and so on are removed, but it's better if >> changes to generic code are supported by public evidence that >> everybody can evaluate. >> >> If you want to pull out the public stuff into a kernel.org bugzilla, >> that would be fine, too. That would actually be better because then >> we don't have to depend on Red Hat maintaining it. > > Agreed (but I couldn't get the vendor to agree to open up the Red Hat > BZ). I've opened https://bugzilla.kernel.org/show_bug.cgi?id=79611 > and included a scrubbed 'dmesg' log there along with an analysis of > how we are hitting the issue. Beautiful, thanks! I marked this for stable and put this in pci/hotplug for v3.17. >>>>> Reference: >>>>> PCI-SIG. PCI Express Base Specification Revision 4.0 Version 0.3 >>>>> (PCI-SIG, 2014): 7.8.11. Slot Status Register (Offset 1Ah). >>>>> >>>>> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> >>>>> --- >>>>> >>>>> drivers/pci/hotplug/pciehp_hpc.c | 2 +- >>>>> 1 files changed, 1 insertions(+), 1 deletions(-) >>>>> >>>>> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c >>>>> index 42914e0..0568416 100644 >>>>> --- a/drivers/pci/hotplug/pciehp_hpc.c >>>>> +++ b/drivers/pci/hotplug/pciehp_hpc.c >>>>> @@ -794,7 +794,7 @@ struct controller *pcie_init(struct pcie_device *dev) >>>>> pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, >>>>> PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | >>>>> PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | >>>>> - PCI_EXP_SLTSTA_CC); >>>>> + PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC); >>>>> >>>>> /* Disable software notification */ >>>>> pcie_disable_notification(ctrl); >>>>> >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >>>> the body of a message to majordomo@vger.kernel.org >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2014-07-07 20:56 UTC | newest] Thread overview: 11+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-06-17 19:27 [PATCH] PCI: pciehp: Include the Data Link Layer State Changed bit when clearing the Slot Status register's event bits Myron Stowe 2014-06-17 21:07 ` Bjorn Helgaas 2014-06-17 22:55 ` Guenter Roeck 2014-06-24 20:34 ` Rajat Jain 2014-06-24 21:16 ` Bjorn Helgaas 2014-06-25 5:26 ` Rajat Jain 2014-06-25 17:51 ` Bjorn Helgaas 2014-06-30 16:49 ` Myron Stowe 2014-07-01 19:29 ` Bjorn Helgaas 2014-07-07 20:26 ` Myron Stowe 2014-07-07 20:56 ` Bjorn Helgaas
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