SWAP_IO_SPACE macro prevents serial driver /drivers/tty/serial/lantiq.c
to use readl/writel to replace ltq_r32/w32 which are SoC or platform
specific APIs.
readl/writel are used for this serial driver to support multiple
platforms and multiple architectures. The legacy lantiq platform(Danube)
enables SWAP_IO_SPACE for supporting PCI due to some hardware bugs.
It's a little-endian bus plus PCI TX/RX swap enable impacted both data
and control path for MIPS based platforms. But it is better to let PCI
device driver to do endian swap since SWAP_IO_SPACE is a global wide macro
which potentially impacts other peripheral like USB.
ltq_r32/ltq_w32 is not impacted in other device drivers based on MIPS when
SWAP_IO_SPACE is not selected as they use non-byte swapping OS API
(__raw_read/__raw_writel).
Signed-off-by: Songjun Wu <songjun...@linux.intel.com>
---
Changes in v2: None
arch/mips/Kconfig | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2d34f17f3e24..2e7e0b538e52 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -400,7 +400,6 @@ config LANTIQ
select SYS_SUPPORTS_VPE_LOADER
select SYS_HAS_EARLY_PRINTK
select GPIOLIB
- select SWAP_IO_SPACE
select BOOT_RAW
select CLKDEV_LOOKUP
select USE_OF
--
2.11.0
