[lkml]   [2020]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 5.5 095/170] ARM: dts: dra7: Add bus_dma_limit for L3 bus
From: Roger Quadros <>

commit cfb5d65f25959f724081bae8445a0241db606af6 upstream.

The L3 interconnect's memory map is from 0x0 to
0xffffffff. Out of this, System memory (SDRAM) can be
accessed from 0x80000000 to 0xffffffff (2GB)

DRA7 does support 4GB of SDRAM but upper 2GB can only be
accessed by the MPU subsystem.

Add the dma-ranges property to reflect the physical address limit
of the L3 bus.

Issues ere observed only with SATA on DRA7-EVM with 4GB RAM
and CONFIG_ARM_LPAE enabled. This is because the controller
supports 64-bit DMA and its driver sets the dma_mask to 64-bit
thus resulting in DMA accesses beyond L3 limit of 2G.

Setting the correct bus_dma_limit fixes the issue.

Signed-off-by: Roger Quadros <>
Signed-off-by: Tony Lindgren <>
Signed-off-by: Greg Kroah-Hartman <>

arch/arm/boot/dts/dra7.dtsi | 1 +
1 file changed, 1 insertion(+)

--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -148,6 +148,7 @@
#address-cells = <1>;
#size-cells = <1>;
ranges = <0x0 0x0 0x0 0xc0000000>;
+ dma-ranges = <0x80000000 0x0 0x80000000 0x80000000>;
ti,hwmods = "l3_main_1", "l3_main_2";
reg = <0x0 0x44000000 0x0 0x1000000>,
<0x0 0x45000000 0x0 0x1000>;

 \ /
  Last update: 2020-03-31 11:06    [W:0.430 / U:1.736 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site