From 8993d5e4662b16845492c413efe82ec162bf5370 Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Tue, 20 Jun 2017 09:43:18 +0200 Subject: nios2: add earlycon support to 3c120 devboard DTS Allow earlycon to be used on the JTAG UART present in the 3c120 GHRD. Signed-off-by: Tobias Klauser --- arch/nios2/boot/dts/3c120_devboard.dts | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/nios2/boot/dts/3c120_devboard.dts b/arch/nios2/boot/dts/3c120_devboard.dts index 31c51f9a2f09..36ccdf05837d 100644 --- a/arch/nios2/boot/dts/3c120_devboard.dts +++ b/arch/nios2/boot/dts/3c120_devboard.dts @@ -159,6 +159,7 @@ }; chosen { - bootargs = "debug console=ttyJ0,115200"; + bootargs = "debug earlycon console=ttyJ0,115200"; + stdout-path = &jtag_uart; }; }; -- cgit v1.2.3-59-g8ed1b From 65d1e3ddeae117f6a224535e10a09145f0f96508 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Mon, 11 Sep 2017 20:45:26 -0700 Subject: nios2: time: Read timer in get_cycles only if initialized Mainline crashes as follows when running nios2 images. On node 0 totalpages: 65536 free_area_init_node: node 0, pgdat c8408fa0, node_mem_map c8726000 Normal zone: 512 pages used for memmap Normal zone: 0 pages reserved Normal zone: 65536 pages, LIFO batch:15 Unable to handle kernel NULL pointer dereference at virtual address 00000000 ea = c8003cb0, ra = c81cbf40, cause = 15 Kernel panic - not syncing: Oops Problem is seen because get_cycles() is called before the timer it depends on is initialized. Returning 0 in that situation fixes the problem. Fixes: 33d72f3822d7 ("init/main.c: extract early boot entropy from the ..") Cc: Laura Abbott Cc: Kees Cook Cc: Daniel Micay Signed-off-by: Guenter Roeck --- arch/nios2/kernel/time.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c index 645129aaa9a0..20e86209ef2e 100644 --- a/arch/nios2/kernel/time.c +++ b/arch/nios2/kernel/time.c @@ -107,7 +107,10 @@ static struct nios2_clocksource nios2_cs = { cycles_t get_cycles(void) { - return nios2_timer_read(&nios2_cs.cs); + /* Only read timer if it has been initialized */ + if (nios2_cs.timer.base) + return nios2_timer_read(&nios2_cs.cs); + return 0; } EXPORT_SYMBOL(get_cycles); -- cgit v1.2.3-59-g8ed1b