Re: [PATCH 1/2] ARM: realview: Fix PBX-A9 cache description
From: Robin Murphy <hidden>
Date: 2016-07-15 17:45:32
Also in:
linux-arm-kernel
On 15/07/16 13:19, Robin Murphy wrote:
Clearly QEMU is very permissive in how its PL310 model may be set up, but the real hardware turns out to be far more particular about things actually being correct. Fix up the DT description so that the real thing actually boots: - The arm,data-latency and arm,tag-latency properties need 3 cells to be valid, otherwise we end up retaining the default 8-cycle latencies which leads pretty quickly to lockup. - The arm,dirty-latency property is only relevant to L210/L220, so get rid of it. - The cache geometry override also leads to lockup and/or general misbehaviour. Irritatingly, the manual doesn't state the actual PL310 configuration, but based on the boardfile code and poking registers from the Boot Monitor, it would seem to be 8 sets of 16KB ways.
FWIW, after an afternoon of bothering people I've tracked down the original spec for the test chip, and can confirm that the configuration is indeed 8x16KB with parity disabled. Robin.
quoted hunk
With that, we can successfully boot to enjoy the fun of mismatched FPUs... Signed-off-by: Robin Murphy <redacted> --- arch/arm/boot/dts/arm-realview-pbx-a9.dts | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)diff --git a/arch/arm/boot/dts/arm-realview-pbx-a9.dts b/arch/arm/boot/dts/arm-realview-pbx-a9.dts index db808f92dd79..90d00b407f85 100644 --- a/arch/arm/boot/dts/arm-realview-pbx-a9.dts +++ b/arch/arm/boot/dts/arm-realview-pbx-a9.dts@@ -70,13 +70,12 @@ * associativity as these may be erroneously set * up by boot loader(s). */ - cache-size = <1048576>; // 1MB - cache-sets = <4096>; + cache-size = <131072>; // 128KB + cache-sets = <512>; cache-line-size = <32>; arm,parity-disable; - arm,tag-latency = <1>; - arm,data-latency = <1 1>; - arm,dirty-latency = <1>; + arm,tag-latency = <1 1 1>; + arm,data-latency = <1 1 1>; }; scu: scu@1f000000 {
-- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html