2016-03-08 18:11:49 +00:00
|
|
|
From 6dcfc3daab7c1c459b36261163b4e1dc15a6e965 Mon Sep 17 00:00:00 2001
|
2016-02-25 10:14:01 +00:00
|
|
|
From: Phil Elwell <phil@raspberrypi.org>
|
|
|
|
|
Date: Wed, 3 Feb 2016 16:12:54 +0000
|
2016-03-08 18:11:49 +00:00
|
|
|
Subject: [PATCH 141/170] BCM270X_DT: Disable DMA for bcm2835-sdhost on Pi2
|
2016-02-25 10:14:01 +00:00
|
|
|
|
|
|
|
|
This is an interim patch to verify that problems seen with
|
|
|
|
|
some cards can be worked around at the expense of an increased
|
|
|
|
|
CPU load by forcing PIO mode.
|
|
|
|
|
|
|
|
|
|
Although this could have used the brcm,force-pio attribute, that
|
|
|
|
|
is a boolean (true if present, false if absent) and attributes
|
|
|
|
|
can't be deleted by overlays. Instead, make brcm,pio-limit
|
|
|
|
|
unfeasibly high instead to allow DMA to be re-enabled using the
|
|
|
|
|
pio_limit parameter of the sdhost or sdtweak overlays.
|
|
|
|
|
---
|
|
|
|
|
arch/arm/boot/dts/bcm2709-rpi-2-b.dts | 1 +
|
|
|
|
|
1 file changed, 1 insertion(+)
|
|
|
|
|
|
|
|
|
|
--- a/arch/arm/boot/dts/bcm2709-rpi-2-b.dts
|
|
|
|
|
+++ b/arch/arm/boot/dts/bcm2709-rpi-2-b.dts
|
|
|
|
|
@@ -43,6 +43,7 @@
|
|
|
|
|
pinctrl-names = "default";
|
|
|
|
|
pinctrl-0 = <&sdhost_pins>;
|
|
|
|
|
bus-width = <4>;
|
|
|
|
|
+ brcm,pio-limit = <0x7fffffff>;
|
|
|
|
|
status = "okay";
|
|
|
|
|
};
|
|
|
|
|
|
