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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Kishon Vijay Abraham I <kishon@ti.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-pci@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 297/671] PCI: dwc: Fix dw_pcie_ep_find_capability() to return correct capability offset
Date: Thu, 16 Jan 2020 11:58:55 -0500
Message-ID: <20200116170509.12787-34-sashal@kernel.org> (raw)
In-Reply-To: <20200116170509.12787-1-sashal@kernel.org>

From: Kishon Vijay Abraham I <kishon@ti.com>

[ 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 <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 739d97080d3b..a3d07d9c598b 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);
 }
 
-- 
2.20.1


  parent reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200116170509.12787-1-sashal@kernel.org>
2020-01-16 16:58 ` [PATCH AUTOSEL 4.19 292/671] PCI: rockchip: Fix rockchip_pcie_ep_assert_intx() bitwise operations Sasha Levin
2020-01-16 16:58 ` Sasha Levin [this message]
2020-01-16 16:59 ` [PATCH AUTOSEL 4.19 321/671] PCI: iproc: Enable iProc config read for PAXBv2 Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 380/671] PCI: PM: Avoid possible suspend-to-idle issue Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 409/671] ntb_hw_switchtec: potential shift wrapping bug in switchtec_ntb_init_sndev() Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 412/671] PCI: PM: Skip devices in D0 for suspend-to-idle Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 447/671] PM: ACPI/PCI: Resume all devices during hibernation Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 454/671] PCI: mobiveil: Remove the flag MSI_FLAG_MULTI_PCI_MSI Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 455/671] PCI: mobiveil: Fix devfn check in mobiveil_pcie_valid_device() Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 456/671] PCI: mobiveil: Fix the valid check for inbound and outbound windows Sasha Levin
2020-01-16 17:04 ` [PATCH AUTOSEL 4.19 622/671] PCI: dwc: Fix find_next_bit() usage Sasha Levin

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