diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0141-BCM270X_DT-Disable-DMA-for-bcm2835-sdhost-on-Pi2.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0141-BCM270X_DT-Disable-DMA-for-bcm2835-sdhost-on-Pi2.patch | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0141-BCM270X_DT-Disable-DMA-for-bcm2835-sdhost-on-Pi2.patch b/target/linux/brcm2708/patches-4.4/0141-BCM270X_DT-Disable-DMA-for-bcm2835-sdhost-on-Pi2.patch new file mode 100644 index 0000000000..40624dbbfe --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0141-BCM270X_DT-Disable-DMA-for-bcm2835-sdhost-on-Pi2.patch @@ -0,0 +1,28 @@ +From 403252ab4bc6c77f2859410e6fa22f3c2bded3e5 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Wed, 3 Feb 2016 16:12:54 +0000 +Subject: [PATCH 141/156] BCM270X_DT: Disable DMA for bcm2835-sdhost on Pi2 + +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"; + }; + |