On 12.05.2015 08:22, Michal Simek wrote:
From: Thomas Betker <thomas.bet...@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")
I've been under the impression that this shouldn't be done in the
kernel, but in the boot loader/firmware:
https://lkml.org/lkml/2015/2/20/199
http://lists.denx.de/pipermail/u-boot/2015-March/207803.html
Best regards
Dirk
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 <punn...@xilinx.com>
Signed-off-by: Thomas Betker <thomas.bet...@rohde-schwarz.com>
Signed-off-by: Michal Simek <michal.si...@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,
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/