From mboxrd@z Thu Jan 1 00:00:00 1970 From: Songjun Wu Subject: [PATCH v2 10/18] MIPS: lantiq: Unselect SWAP_IO_SPACE when LANTIQ is selected Date: Fri, 3 Aug 2018 11:02:29 +0800 Message-ID: <20180803030237.3366-11-songjun.wu@linux.intel.com> References: <20180803030237.3366-1-songjun.wu@linux.intel.com> Return-path: In-Reply-To: <20180803030237.3366-1-songjun.wu@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: hua.ma@linux.intel.com, yixin.zhu@linux.intel.com, chuanhua.lei@linux.intel.com, qi-ming.wu@intel.com Cc: linux-mips@linux-mips.org, linux-clk@vger.kernel.org, linux-serial@vger.kernel.org, devicetree@vger.kernel.org, Songjun Wu , Ralf Baechle , Paul Burton , James Hogan , linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org 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 --- 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