[PATCH V10 08/12] powerpc/powernv: Support EEH reset for VF PE
PEs for VFs don't have primary bus. So they have to have their own reset backend, which is used during EEH recovery. The patch implements the reset backend for VF's PE by issuing FLR or AF FLR to the VFs, which are contained in the PE. [gwshan: changelog and code refactoring] Signed-off-by: Wei Yang Acked-by: Gavin Shan --- arch/powerpc/include/asm/eeh.h | 1 + arch/powerpc/platforms/powernv/eeh-powernv.c | 134 ++- 2 files changed, 134 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index ec21f8f..331c856 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -136,6 +136,7 @@ struct eeh_dev { int pcix_cap; /* Saved PCIx capability*/ int pcie_cap; /* Saved PCIe capability*/ int aer_cap;/* Saved AER capability */ + int af_cap; /* Saved AF capability */ struct eeh_pe *pe; /* Associated PE*/ struct list_head list; /* Form link list in the PE */ struct pci_controller *phb; /* Associated PHB */ diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index cfd55dd..017cd72 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c @@ -404,6 +404,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data) edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX); edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP); edev->aer_cap = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR); + edev->af_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF); if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) { edev->mode |= EEH_DEV_BRIDGE; if (edev->pcie_cap) { @@ -893,6 +894,127 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) return 0; } +static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, int pos, +u16 mask, bool af_flr_rst) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + int status, i; + + /* Wait for Transaction Pending bit to be cleared */ + for (i = 0; i < 4; i++) { + eeh_ops->read_config(pdn, pos, 2, &status); + if (!(status & mask)) + return; + + msleep((1 << i) * 100); + } + + pr_warn("%s: Pending transaction while issuing %s FLR to " + "%04x:%02x:%02x.%01x\n", + __func__, af_flr_rst ? "AF" : "", + edev->phb->global_number, pdn->busno, + PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); +} + +static int pnv_eeh_do_flr(struct pci_dn *pdn, int option) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + u32 reg; + + if (!edev->pcie_cap) + return -ENOTTY; + + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCAP, 4, ®); + if (!(reg & PCI_EXP_DEVCAP_FLR)) + return -ENOTTY; + + switch (option) { + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + pnv_eeh_wait_for_pending(pdn, edev->pcie_cap + PCI_EXP_DEVSTA, +PCI_EXP_DEVSTA_TRPND, false); + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, +4, ®); + reg |= PCI_EXP_DEVCTL_BCR_FLR; + eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, + 4, reg); + msleep(EEH_PE_RST_HOLD_TIME); + break; + case EEH_RESET_DEACTIVATE: + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, +4, ®); + reg &= ~PCI_EXP_DEVCTL_BCR_FLR; + eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, + 4, reg); + msleep(EEH_PE_RST_SETTLE_TIME); + break; + } + + return 0; +} + +static int pnv_eeh_do_af_flr(struct pci_dn *pdn, int option) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + u32 cap; + + if (!edev->af_cap) + return -ENOTTY; + + eeh_ops->read_config(pdn, edev->af_cap + PCI_AF_CAP, 1, &cap); + if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) + return -ENOTTY; + + switch (option) { + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + /* +* Wait for Transaction Pending bit to clear. A word-aligned +* test is used, so we use the conrol offset rather than status +* and shift the test bit to match. +*/ + pnv_eeh_wait_for_pending(pdn, edev->af_cap +
Re: [PATCH V10 08/12] powerpc/powernv: Support EEH reset for VF PE
On 10/26/2015 02:15 PM, Wei Yang wrote: PEs for VFs don't have primary bus. So they have to have their own reset backend, which is used during EEH recovery. The patch implements the reset backend for VF's PE by issuing FLR or AF FLR to the VFs, which are contained in the PE. [gwshan: changelog and code refactoring] Signed-off-by: Wei Yang Acked-by: Gavin Shan --- arch/powerpc/include/asm/eeh.h | 1 + arch/powerpc/platforms/powernv/eeh-powernv.c | 134 ++- 2 files changed, 134 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index ec21f8f..331c856 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -136,6 +136,7 @@ struct eeh_dev { int pcix_cap; /* Saved PCIx capability*/ int pcie_cap; /* Saved PCIe capability*/ int aer_cap;/* Saved AER capability */ + int af_cap; /* Saved AF capability */ struct eeh_pe *pe; /* Associated PE*/ struct list_head list; /* Form link list in the PE */ struct pci_controller *phb; /* Associated PHB */ diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index cfd55dd..017cd72 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c @@ -404,6 +404,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data) edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX); edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP); edev->aer_cap = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR); + edev->af_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF); if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) { edev->mode |= EEH_DEV_BRIDGE; if (edev->pcie_cap) { @@ -893,6 +894,127 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) return 0; } +static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, int pos, +u16 mask, bool af_flr_rst) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + int status, i; + + /* Wait for Transaction Pending bit to be cleared */ + for (i = 0; i < 4; i++) { + eeh_ops->read_config(pdn, pos, 2, &status); gcc should have complained on using uninitialized @status here. + if (!(status & mask)) + return; + + msleep((1 << i) * 100); + } + + pr_warn("%s: Pending transaction while issuing %s FLR to " + "%04x:%02x:%02x.%01x\n", Do not wrap user-visible strings. + __func__, af_flr_rst ? "AF" : "", + edev->phb->global_number, pdn->busno, + PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); +} + +static int pnv_eeh_do_flr(struct pci_dn *pdn, int option) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + u32 reg; + + if (!edev->pcie_cap) + return -ENOTTY; Can pnv_eeh_do_flr() be really called on a non PCIe device, can we get that far? WARN_ON_ONCE() may be? + + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCAP, 4, ®); ... and here about uninitialized @reg. + if (!(reg & PCI_EXP_DEVCAP_FLR)) + return -ENOTTY; + + switch (option) { + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + pnv_eeh_wait_for_pending(pdn, edev->pcie_cap + PCI_EXP_DEVSTA, +PCI_EXP_DEVSTA_TRPND, false); + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, +4, ®); + reg |= PCI_EXP_DEVCTL_BCR_FLR; + eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, + 4, reg); + msleep(EEH_PE_RST_HOLD_TIME); + break; + case EEH_RESET_DEACTIVATE: + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, +4, ®); + reg &= ~PCI_EXP_DEVCTL_BCR_FLR; + eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, + 4, reg); + msleep(EEH_PE_RST_SETTLE_TIME); + break; + } + + return 0; +} + +static int pnv_eeh_do_af_flr(struct pci_dn *pdn, int option) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + u32 cap; + + if (!edev->af_cap) + return -ENOTTY; + + eeh_ops->read_config(pdn, edev->af_cap + PCI_AF_CAP, 1, &cap); ... and here about @cap. + if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) + return -ENOTTY; + + switch (option) { + case EEH_RESET_HOT: +
Re: [PATCH V10 08/12] powerpc/powernv: Support EEH reset for VF PE
On Fri, Oct 30, 2015 at 03:11:20PM +1100, Alexey Kardashevskiy wrote: >On 10/26/2015 02:15 PM, Wei Yang wrote: >>PEs for VFs don't have primary bus. So they have to have their own reset >>backend, which is used during EEH recovery. The patch implements the reset >>backend for VF's PE by issuing FLR or AF FLR to the VFs, which are contained >>in the PE. >> >>[gwshan: changelog and code refactoring] >>Signed-off-by: Wei Yang >>Acked-by: Gavin Shan >>--- >> arch/powerpc/include/asm/eeh.h | 1 + >> arch/powerpc/platforms/powernv/eeh-powernv.c | 134 >> ++- >> 2 files changed, 134 insertions(+), 1 deletion(-) >> >>diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h >>index ec21f8f..331c856 100644 >>--- a/arch/powerpc/include/asm/eeh.h >>+++ b/arch/powerpc/include/asm/eeh.h >>@@ -136,6 +136,7 @@ struct eeh_dev { >> int pcix_cap; /* Saved PCIx capability*/ >> int pcie_cap; /* Saved PCIe capability*/ >> int aer_cap;/* Saved AER capability */ >>+ int af_cap; /* Saved AF capability */ >> struct eeh_pe *pe; /* Associated PE*/ >> struct list_head list; /* Form link list in the PE */ >> struct pci_controller *phb; /* Associated PHB */ >>diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c >>b/arch/powerpc/platforms/powernv/eeh-powernv.c >>index cfd55dd..017cd72 100644 >>--- a/arch/powerpc/platforms/powernv/eeh-powernv.c >>+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c >>@@ -404,6 +404,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data) >> edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX); >> edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP); >> edev->aer_cap = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR); >>+ edev->af_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF); >> if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) { >> edev->mode |= EEH_DEV_BRIDGE; >> if (edev->pcie_cap) { >>@@ -893,6 +894,127 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, >>int option) >> return 0; >> } >> >>+static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, int pos, >>+ u16 mask, bool af_flr_rst) >>+{ >>+ struct eeh_dev *edev = pdn_to_eeh_dev(pdn); >>+ int status, i; >>+ >>+ /* Wait for Transaction Pending bit to be cleared */ >>+ for (i = 0; i < 4; i++) { >>+ eeh_ops->read_config(pdn, pos, 2, &status); > > >gcc should have complained on using uninitialized @status here. > I remove the obj file and re-compile the file, not the warning. And took a look at other places where read_config() is called. The laster parameter is not initialized before called. You see the error during build? > >>+ if (!(status & mask)) >>+ return; >>+ >>+ msleep((1 << i) * 100); >>+ } >>+ >>+ pr_warn("%s: Pending transaction while issuing %s FLR to " >>+ "%04x:%02x:%02x.%01x\n", > >Do not wrap user-visible strings. > Will change this. > >>+ __func__, af_flr_rst ? "AF" : "", >>+ edev->phb->global_number, pdn->busno, >>+ PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); >>+} >>+ >>+static int pnv_eeh_do_flr(struct pci_dn *pdn, int option) >>+{ >>+ struct eeh_dev *edev = pdn_to_eeh_dev(pdn); >>+ u32 reg; >>+ >>+ if (!edev->pcie_cap) >>+ return -ENOTTY; > > >Can pnv_eeh_do_flr() be really called on a non PCIe device, can we get that >far? WARN_ON_ONCE() may be? > So you suggest to add a WARN_ON_ONCE() in this condition, right? > >>+ >>+ eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCAP, 4, ®); > > >... and here about uninitialized @reg. > > >>+ if (!(reg & PCI_EXP_DEVCAP_FLR)) >>+ return -ENOTTY; >>+ >>+ switch (option) { >>+ case EEH_RESET_HOT: >>+ case EEH_RESET_FUNDAMENTAL: >>+ pnv_eeh_wait_for_pending(pdn, edev->pcie_cap + PCI_EXP_DEVSTA, >>+ PCI_EXP_DEVSTA_TRPND, false); >>+ eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, >>+ 4, ®); >>+ reg |= PCI_EXP_DEVCTL_BCR_FLR; >>+ eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, >>+ 4, reg); >>+ msleep(EEH_PE_RST_HOLD_TIME); >>+ break; >>+ case EEH_RESET_DEACTIVATE: >>+ eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, >>+ 4, ®); >>+ reg &= ~PCI_EXP_DEVCTL_BCR_FLR; >>+ eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, >>+ 4, reg); >>+ msleep(EEH_PE_RST_SETTLE_TIME); >>+ break; >>+ } >>+ >>+
Re: [PATCH V10 08/12] powerpc/powernv: Support EEH reset for VF PE
On 10/30/2015 06:18 PM, Wei Yang wrote: On Fri, Oct 30, 2015 at 03:11:20PM +1100, Alexey Kardashevskiy wrote: On 10/26/2015 02:15 PM, Wei Yang wrote: PEs for VFs don't have primary bus. So they have to have their own reset backend, which is used during EEH recovery. The patch implements the reset backend for VF's PE by issuing FLR or AF FLR to the VFs, which are contained in the PE. [gwshan: changelog and code refactoring] Signed-off-by: Wei Yang Acked-by: Gavin Shan --- arch/powerpc/include/asm/eeh.h | 1 + arch/powerpc/platforms/powernv/eeh-powernv.c | 134 ++- 2 files changed, 134 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index ec21f8f..331c856 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -136,6 +136,7 @@ struct eeh_dev { int pcix_cap; /* Saved PCIx capability*/ int pcie_cap; /* Saved PCIe capability*/ int aer_cap;/* Saved AER capability */ + int af_cap; /* Saved AF capability */ struct eeh_pe *pe; /* Associated PE*/ struct list_head list; /* Form link list in the PE */ struct pci_controller *phb; /* Associated PHB */ diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index cfd55dd..017cd72 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c @@ -404,6 +404,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data) edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX); edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP); edev->aer_cap = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR); + edev->af_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF); if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) { edev->mode |= EEH_DEV_BRIDGE; if (edev->pcie_cap) { @@ -893,6 +894,127 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) return 0; } +static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, int pos, +u16 mask, bool af_flr_rst) Missed this - @af_flr_rst is only used for warnings so better do: s/bool af_flr_rst/const char *reset_type/ to make it explicit. +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + int status, i; + + /* Wait for Transaction Pending bit to be cleared */ + for (i = 0; i < 4; i++) { + eeh_ops->read_config(pdn, pos, 2, &status); gcc should have complained on using uninitialized @status here. I remove the obj file and re-compile the file, not the warning. Hm. Does not warn me either. And took a look at other places where read_config() is called. The laster parameter is not initialized before called. So? It does not make it right. You see the error during build? Why does it matter? We have an undefined behavior here which we should not. You could test the return values from read_config() but you do not so at least initialize local variables. + if (!(status & mask)) + return; + + msleep((1 << i) * 100); + } + + pr_warn("%s: Pending transaction while issuing %s FLR to " + "%04x:%02x:%02x.%01x\n", Do not wrap user-visible strings. Will change this. + __func__, af_flr_rst ? "AF" : "", + edev->phb->global_number, pdn->busno, + PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); +} + +static int pnv_eeh_do_flr(struct pci_dn *pdn, int option) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + u32 reg; + + if (!edev->pcie_cap) + return -ENOTTY; Can pnv_eeh_do_flr() be really called on a non PCIe device, can we get that far? WARN_ON_ONCE() may be? So you suggest to add a WARN_ON_ONCE() in this condition, right? I am asking a question here whether it makes sense or not to add a WARN_ON_ONCE or replace "if" with WARN_ON_ONCE or not having pcie_cap initialized is possible in this code - which one is it? + + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCAP, 4, ®); ... and here about uninitialized @reg. + if (!(reg & PCI_EXP_DEVCAP_FLR)) + return -ENOTTY; + + switch (option) { + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + pnv_eeh_wait_for_pending(pdn, edev->pcie_cap + PCI_EXP_DEVSTA, +PCI_EXP_DEVSTA_TRPND, false); + eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, +4, ®); + reg |= PCI_EXP_DEVCTL_BCR_FLR; + eeh_ops->write_config(pdn, edev->pcie_cap + PC
Re: [PATCH V10 08/12] powerpc/powernv: Support EEH reset for VF PE
On Fri, Oct 30, 2015 at 07:05:05PM +1100, Alexey Kardashevskiy wrote: >On 10/30/2015 06:18 PM, Wei Yang wrote: >>On Fri, Oct 30, 2015 at 03:11:20PM +1100, Alexey Kardashevskiy wrote: >>>On 10/26/2015 02:15 PM, Wei Yang wrote: PEs for VFs don't have primary bus. So they have to have their own reset backend, which is used during EEH recovery. The patch implements the reset backend for VF's PE by issuing FLR or AF FLR to the VFs, which are contained in the PE. [gwshan: changelog and code refactoring] Signed-off-by: Wei Yang Acked-by: Gavin Shan --- arch/powerpc/include/asm/eeh.h | 1 + arch/powerpc/platforms/powernv/eeh-powernv.c | 134 ++- 2 files changed, 134 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index ec21f8f..331c856 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -136,6 +136,7 @@ struct eeh_dev { int pcix_cap; /* Saved PCIx capability*/ int pcie_cap; /* Saved PCIe capability*/ int aer_cap;/* Saved AER capability */ + int af_cap; /* Saved AF capability */ struct eeh_pe *pe; /* Associated PE*/ struct list_head list; /* Form link list in the PE */ struct pci_controller *phb; /* Associated PHB */ diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c index cfd55dd..017cd72 100644 --- a/arch/powerpc/platforms/powernv/eeh-powernv.c +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c @@ -404,6 +404,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data) edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX); edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP); edev->aer_cap = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR); + edev->af_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF); if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) { edev->mode |= EEH_DEV_BRIDGE; if (edev->pcie_cap) { @@ -893,6 +894,127 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option) return 0; } +static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, int pos, +u16 mask, bool af_flr_rst) > >Missed this - @af_flr_rst is only used for warnings so better do: >s/bool af_flr_rst/const char *reset_type/ >to make it explicit. > Looks good, will change in next version. > +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + int status, i; + + /* Wait for Transaction Pending bit to be cleared */ + for (i = 0; i < 4; i++) { + eeh_ops->read_config(pdn, pos, 2, &status); >>> >>> >>>gcc should have complained on using uninitialized @status here. >>> >> >>I remove the obj file and re-compile the file, not the warning. > >Hm. Does not warn me either. > >>And took a look at other places where read_config() is called. The laster >>parameter is not initialized before called. > >So? It does not make it right. > >>You see the error during build? > >Why does it matter? We have an undefined behavior here which we should not. >You could test the return values from read_config() but you do not so at >least initialize local variables. > I believe your concern is reasonable. I suggest to have a separate patch to fix the read_config() by initialize the last parameter. > >> >>> + if (!(status & mask)) + return; + + msleep((1 << i) * 100); + } + + pr_warn("%s: Pending transaction while issuing %s FLR to " + "%04x:%02x:%02x.%01x\n", >>> >>>Do not wrap user-visible strings. >>> >> >>Will change this. >> >>> + __func__, af_flr_rst ? "AF" : "", + edev->phb->global_number, pdn->busno, + PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); +} + +static int pnv_eeh_do_flr(struct pci_dn *pdn, int option) +{ + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + u32 reg; + + if (!edev->pcie_cap) + return -ENOTTY; >>> >>> >>>Can pnv_eeh_do_flr() be really called on a non PCIe device, can we get that >>>far? WARN_ON_ONCE() may be? >>> >> >>So you suggest to add a WARN_ON_ONCE() in this condition, right? > >I am asking a question here whether it makes sense or not to add a >WARN_ON_ONCE or replace "if" with WARN_ON_ONCE or not having pcie_cap >initialized is possible in this code - which one is it? > I think the check here is reasonable. In the body of this function, pcie_cap is used to access the config space. If we remove this, it would be a chance to access a not correct area. > >> >>> >