| Message ID | 20190325093947.32633-21-kishon@ti.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | e4620a6b3c1e69d590286aa5c4161ab5ccb1278b |
| Headers | show |
| Series | Add support for PCIe RC and EP mode in TI's AM654 SoC | expand |
On Mon, Mar 25, 2019 at 03:09:41PM +0530, Kishon Vijay Abraham I wrote: > commit beb4641a787df79a ("PCI: dwc: Add MSI-X callbacks handler") while > adding MSI-X callback handler, introduced dw_pcie_ep_find_capability and > __dw_pcie_ep_find_next_cap for finding the MSI and MSIX capability. > > However if MSI or MSIX capability is the last capability (i.e there are > no additional items in the capabilities list and the Next Capability > Pointer is set to '0'), __dw_pcie_ep_find_next_cap will return '0' > even though MSI or MSIX capability may be present. This is because of > incorrect ordering of "next_cap_ptr" check. Fix it here. Nice fix. It looks like dw_pcie_ep_find_capability() is currently only used for MSI and MSI-X, but IIUC, it *could* be used for any capability, so this commit message seems a little too specific. It would be slightly less confusing if beb4641a787d ("PCI: dwc: Add MSI-X callbacks handler") had been split into a commit that added the general-purpose dw_pcie_ep_find_capability() and a commit that used it for MSI and MSI-X, but obviously we can't change history. > Fixes: beb4641a787df79a142 ("PCI: dwc: Add MSI-X callbacks handler") These commit references are longer than necessary (and different - 19-char SHA1 here and 16 chars above). I typically use 12 chars via gsr is aliased to `git --no-pager show -s --abbrev-commit --abbrev=12 --pretty=format:"%h (\"%s\")%n"' > Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> > --- > drivers/pci/controller/dwc/pcie-designware-ep.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c > index dc6a4bbd3ace..74477ad7467f 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > @@ -46,16 +46,19 @@ static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr, > u8 cap_id, next_cap_ptr; > u16 reg; > > + if (!cap_ptr) > + return 0; > + > reg = dw_pcie_readw_dbi(pci, cap_ptr); > - next_cap_ptr = (reg & 0xff00) >> 8; > cap_id = (reg & 0x00ff); > > - if (!next_cap_ptr || cap_id > PCI_CAP_ID_MAX) > + if (cap_id > PCI_CAP_ID_MAX) > return 0; > > if (cap_id == cap) > return cap_ptr; > > + next_cap_ptr = (reg & 0xff00) >> 8; > return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); > } > > @@ -67,9 +70,6 @@ static u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap) > reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST); > next_cap_ptr = (reg & 0x00ff); > > - if (!next_cap_ptr) > - return 0; > - > return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); > } > > -- > 2.17.1 >
On Sat, Apr 13, 2019 at 10:44:37AM -0500, Bjorn Helgaas wrote: > On Mon, Mar 25, 2019 at 03:09:41PM +0530, Kishon Vijay Abraham I wrote: > > commit beb4641a787df79a ("PCI: dwc: Add MSI-X callbacks handler") while > > adding MSI-X callback handler, introduced dw_pcie_ep_find_capability and > > __dw_pcie_ep_find_next_cap for finding the MSI and MSIX capability. > > > > However if MSI or MSIX capability is the last capability (i.e there are > > no additional items in the capabilities list and the Next Capability > > Pointer is set to '0'), __dw_pcie_ep_find_next_cap will return '0' > > even though MSI or MSIX capability may be present. This is because of > > incorrect ordering of "next_cap_ptr" check. Fix it here. > > Nice fix. It looks like dw_pcie_ep_find_capability() is currently > only used for MSI and MSI-X, but IIUC, it *could* be used for any > capability, so this commit message seems a little too specific. > > It would be slightly less confusing if beb4641a787d ("PCI: dwc: Add > MSI-X callbacks handler") had been split into a commit that added the > general-purpose dw_pcie_ep_find_capability() and a commit that used it > for MSI and MSI-X, but obviously we can't change history. > > > Fixes: beb4641a787df79a142 ("PCI: dwc: Add MSI-X callbacks handler") > > These commit references are longer than necessary (and different - > 19-char SHA1 here and 16 chars above). I typically use 12 chars via > > gsr is aliased to `git --no-pager show -s --abbrev-commit --abbrev=12 --pretty=format:"%h (\"%s\")%n"' Fixed while queueing it. Thanks, Lorenzo > > > Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> > > --- > > drivers/pci/controller/dwc/pcie-designware-ep.c | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c > > index dc6a4bbd3ace..74477ad7467f 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c > > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c > > @@ -46,16 +46,19 @@ static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr, > > u8 cap_id, next_cap_ptr; > > u16 reg; > > > > + if (!cap_ptr) > > + return 0; > > + > > reg = dw_pcie_readw_dbi(pci, cap_ptr); > > - next_cap_ptr = (reg & 0xff00) >> 8; > > cap_id = (reg & 0x00ff); > > > > - if (!next_cap_ptr || cap_id > PCI_CAP_ID_MAX) > > + if (cap_id > PCI_CAP_ID_MAX) > > return 0; > > > > if (cap_id == cap) > > return cap_ptr; > > > > + next_cap_ptr = (reg & 0xff00) >> 8; > > return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); > > } > > > > @@ -67,9 +70,6 @@ static u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap) > > reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST); > > next_cap_ptr = (reg & 0x00ff); > > > > - if (!next_cap_ptr) > > - return 0; > > - > > return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); > > } > > > > -- > > 2.17.1 > >
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c index dc6a4bbd3ace..74477ad7467f 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -46,16 +46,19 @@ static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr, u8 cap_id, next_cap_ptr; u16 reg; + if (!cap_ptr) + return 0; + reg = dw_pcie_readw_dbi(pci, cap_ptr); - next_cap_ptr = (reg & 0xff00) >> 8; cap_id = (reg & 0x00ff); - if (!next_cap_ptr || cap_id > PCI_CAP_ID_MAX) + if (cap_id > PCI_CAP_ID_MAX) return 0; if (cap_id == cap) return cap_ptr; + next_cap_ptr = (reg & 0xff00) >> 8; return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); } @@ -67,9 +70,6 @@ static u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap) reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST); next_cap_ptr = (reg & 0x00ff); - if (!next_cap_ptr) - return 0; - return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap); }
commit beb4641a787df79a ("PCI: dwc: Add MSI-X callbacks handler") while adding MSI-X callback handler, introduced dw_pcie_ep_find_capability and __dw_pcie_ep_find_next_cap for finding the MSI and MSIX capability. However if MSI or MSIX capability is the last capability (i.e there are no additional items in the capabilities list and the Next Capability Pointer is set to '0'), __dw_pcie_ep_find_next_cap will return '0' even though MSI or MSIX capability may be present. This is because of incorrect ordering of "next_cap_ptr" check. Fix it here. Fixes: beb4641a787df79a142 ("PCI: dwc: Add MSI-X callbacks handler") Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> --- drivers/pci/controller/dwc/pcie-designware-ep.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)