[PATCH AUTOSEL 4.9 07/34] MIPS: loongson64: cs5536: Fix PCI_OHCI_INT_REG reads

Sasha Levin
2018-09-15T01:40:51Z

From: Paul Burton <paul.burton@mips.com>

[ Upstream commit cd87668d601f622e0ebcfea4f78d116d5f572f4d ]

The PCI_OHCI_INT_REG case in pci_ohci_read_reg() contains the following
if statement:

if ((lo & 0x00000f00) == CS5536_USB_INTR)

CS5536_USB_INTR expands to the constant 11, which gives us the following
condition which can never evaluate true:

if ((lo & 0xf00) == 11)

At least when using GCC 8.1.0 this falls foul of the tautoligcal-compare
warning, and since the code is built with the -Werror flag the build
fails.

Fix this by shifting lo right by 8 bits in order to match the
corresponding PCI_OHCI_INT_REG case in pci_ohci_write_reg().

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19861/
Cc: Huacai Chen <chenhc@lemote.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
arch/mips/loongson64/common/cs5536/cs5536_ohci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/loongson64/common/cs5536/cs5536_ohci.c b/arch/mips/loongson64/common/cs5536/cs5536_ohci.c
index f7c905e50dc4..92dc6bafc127 100644
--- a/arch/mips/loongson64/common/cs5536/cs5536_ohci.c
+++ b/arch/mips/loongson64/common/cs5536/cs5536_ohci.c
@@ -138,7 +138,7 @@ u32 pci_ohci_read_reg(int reg)
break;
case PCI_OHCI_INT_REG:
_rdmsr(DIVIL_MSR_REG(PIC_YSEL_LOW), &hi, &lo);
- if ((lo & 0x00000f00) == CS5536_USB_INTR)
+ if (((lo >> PIC_YSEL_LOW_USB_SHIFT) & 0xf) == CS5536_USB_INTR)
conf_data = 1;
break;
default:
--
2.17.1