From 3794705aeb318c431c07072f04380c78cc5a84ac Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Thu, 23 Oct 2014 17:38:31 +0300 Subject: [PATCH] ARM: shmobile: Select CONFIG_ZONE_DMA when CONFIG_ARM_LPAE is enabled Most IP cores on ARM Renesas platforms can only address 32 bits of physical memory for DMA. Without CONFIG_ZONE_DMA enabled and with the recent CMA highmem allocation support, the default CMA zone is reserved above the 4GiB limit when LPAE is enabled, resulting in various driver failures. Fix the problem by selecting CONFIG_ZONE_DMA. Other options to investigate in the future would be to either enable IOMMU support or use custom CMA reservations for peripherals not supporting LPAE. While not a strict dependency, the "[PATCH 0/4] Low/high memory CMA reservation fixes" series is also required to fix a different but related CMA allocation problem. Signed-off-by: Laurent Pinchart Signed-off-by: Simon Horman --- arch/arm/mach-shmobile/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig index 21f457b56c01..6bc018fc5dc1 100644 --- a/arch/arm/mach-shmobile/Kconfig +++ b/arch/arm/mach-shmobile/Kconfig @@ -1,5 +1,6 @@ config ARCH_SHMOBILE bool + select ZONE_DMA if ARM_LPAE config PM_RCAR bool -- 2.20.1