From 1159872c91639a33d3f812d06e9dda08b71e3b1a Mon Sep 17 00:00:00 2001 From: Kishon Vijay Abraham I Date: Mon, 25 Mar 2019 15:09:41 +0530 Subject: [PATCH] PCI: dwc: Fix dw_pcie_ep_find_capability() to return correct capability offset [ Upstream commit 421db1ab287eebe80fd203eb009ae92836c586ad ] commit beb4641a787d ("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 because of incorrect ordering of the "next_cap_ptr" check. Fix it. Fixes: beb4641a787d ("PCI: dwc: Add MSI-X callbacks handler") Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Lorenzo Pieralisi Signed-off-by: Sasha Levin --- 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 739d97080d3bd..a3d07d9c598bf 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); } -- 2.47.3