Messages in this thread Patch in this message | | | From | Michal Simek <> | Subject | [PATCH] ARM: zynq: Set bit 22 in PL310 AuxCtrl register (6395/1) | Date | Tue, 12 May 2015 08:22:01 +0200 |
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From: Thomas Betker <thomas.betker@rohde-schwarz.com>
This patch is based on the commit 1a8e41cd672f ("ARM: 6395/1: VExpress: Set bit 22 in the PL310 (cache controller) AuxCtlr register")
Clearing bit 22 in the PL310 Auxiliary Control register (shared attribute override enable) has the side effect of transforming Normal Shared Non-cacheable reads into Cacheable no-allocate reads.
Coherent DMA buffers in Linux always have a cacheable alias via the kernel linear mapping and the processor can speculatively load cache lines into the PL310 controller. With bit 22 cleared, Non-cacheable reads would unexpectedly hit such cache lines leading to buffer corruption.
For Zynq, this fix avoids memory inconsistencies between Gigabit Ethernet controller (GEM) and CPU when DMA_CMA is disabled.
Suggested-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com> Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> ---
arch/arm/mach-zynq/common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c index 39c1c7d43522..af36dc2545c1 100644 --- a/arch/arm/mach-zynq/common.c +++ b/arch/arm/mach-zynq/common.c @@ -197,8 +197,8 @@ static const char * const zynq_dt_match[] = { DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform") /* 64KB way size, 8-way associativity, parity disabled */ - .l2c_aux_val = 0x00000000, - .l2c_aux_mask = 0xffffffff, + .l2c_aux_val = 0x00400000, + .l2c_aux_mask = 0xffbfffff, .smp = smp_ops(zynq_smp_ops), .map_io = zynq_map_io, .init_irq = zynq_irq_init, -- 2.3.5
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