diff options
Diffstat (limited to 'target/linux/pistachio/patches-4.9/109-MIPS-DTS-img-marduk-switch-mmc-to-1-bit-mode.patch')
| -rw-r--r-- | target/linux/pistachio/patches-4.9/109-MIPS-DTS-img-marduk-switch-mmc-to-1-bit-mode.patch | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/target/linux/pistachio/patches-4.9/109-MIPS-DTS-img-marduk-switch-mmc-to-1-bit-mode.patch b/target/linux/pistachio/patches-4.9/109-MIPS-DTS-img-marduk-switch-mmc-to-1-bit-mode.patch new file mode 100644 index 0000000000..141e401fcb --- /dev/null +++ b/target/linux/pistachio/patches-4.9/109-MIPS-DTS-img-marduk-switch-mmc-to-1-bit-mode.patch @@ -0,0 +1,52 @@ +From 981c1d416af45eff207227aec106381ac23aac99 Mon Sep 17 00:00:00 2001 +From: Ian Pozella <Ian.Pozella@imgtec.com> +Date: Mon, 20 Feb 2017 10:00:52 +0000 +Subject: MIPS: DTS: img: marduk: switch mmc to 1 bit mode + +The mmc block in Pistachio allows 1 to 8 data bits to be used. +Marduk uses 4 bits allowing the upper 4 bits to be allocated +to the Mikrobus ports. However these bits are still connected +internally meaning the mmc block recieves signals on all data lines +and seems the internal HW CRC checks get corrupted by this erroneous +data. + +We cannot control what data is sent on these lines because they go +to external ports. 1 bit mode does not exhibit the issue hence the +safe default is to use this. If a user knows that in their use case +they will not use the upper bits then they can set to 4 bit mode in +order to improve performance. + +Also make sure that the upper 4 bits don't get allocated to the mmc +driver (the default is to assign all 8 pins) so they can be allocated +to other drivers. Allocating all 4 despite setting 1 bit mode as this +matches what is there in hardware. + +Signed-off-by: Ian Pozella <Ian.Pozella@imgtec.com> +--- + arch/mips/boot/dts/img/pistachio_marduk.dts | 3 ++- + 1 file changed, 2 insertions(+), 1 deletion(-) + +diff --git a/arch/mips/boot/dts/img/pistachio_marduk.dts b/arch/mips/boot/dts/img/pistachio_marduk.dts +index cf9cebd..7708815 100644 +--- a/arch/mips/boot/dts/img/pistachio_marduk.dts ++++ b/arch/mips/boot/dts/img/pistachio_marduk.dts +@@ -120,7 +120,7 @@ + + &sdhost { + status = "okay"; +- bus-width = <4>; ++ bus-width = <1>; + disable-wp; + }; + +@@ -130,6 +130,7 @@ + + &pin_sdhost_data { + drive-strength = <2>; ++ pins = "mfio17", "mfio18", "mfio19", "mfio20"; + }; + + &pwm { +-- +2.7.4 + |