From 6acb53c5267b96aa4f166c703998eaad3cb5d9fd Mon Sep 17 00:00:00 2001 From: John Crispin Date: Tue, 25 Jul 2017 14:46:01 +0200 Subject: ralink: fix rcu_sched stalls on mt7621 there were 2 bugs *) core1 came up with a bad bogo mips, looks like the clock needed time to stabilize *) HPT frequency was not set making r4k timers not come up properly Signed-off-by: John Crispin --- target/linux/ramips/dts/mt7621.dtsi | 13 +++ .../ramips/patches-4.9/101-mt7621-timer.patch | 119 +++++++++++++++++++++ 2 files changed, 132 insertions(+) create mode 100644 target/linux/ramips/patches-4.9/101-mt7621-timer.patch diff --git a/target/linux/ramips/dts/mt7621.dtsi b/target/linux/ramips/dts/mt7621.dtsi index 6b95c54bef..7662518992 100644 --- a/target/linux/ramips/dts/mt7621.dtsi +++ b/target/linux/ramips/dts/mt7621.dtsi @@ -42,6 +42,8 @@ clock-frequency = <50000000>; }; + + palmbus: palmbus@1E000000 { compatible = "palmbus"; reg = <0x1E000000 0x100000>; @@ -129,6 +131,17 @@ status = "disabled"; }; + systick: systick@d00 { + compatible = "ralink,mt7621-systick", "ralink,cevt-systick"; + reg = <0xd00 0x10>; + + resets = <&rstctrl 28>; + reset-names = "intc"; + + interrupt-parent = <&gic>; + interrupts = ; + }; + memc: memc@5000 { compatible = "mtk,mt7621-memc"; reg = <0x300 0x100>; diff --git a/target/linux/ramips/patches-4.9/101-mt7621-timer.patch b/target/linux/ramips/patches-4.9/101-mt7621-timer.patch new file mode 100644 index 0000000000..ca90f5d0e3 --- /dev/null +++ b/target/linux/ramips/patches-4.9/101-mt7621-timer.patch @@ -0,0 +1,119 @@ +Index: linux-4.9.37/arch/mips/kernel/smp-cmp.c +=================================================================== +--- linux-4.9.37.orig/arch/mips/kernel/smp-cmp.c ++++ linux-4.9.37/arch/mips/kernel/smp-cmp.c +@@ -43,6 +43,10 @@ static void cmp_init_secondary(void) + { + struct cpuinfo_mips *c __maybe_unused = ¤t_cpu_data; + ++ printk("%s:%s[%d]%x\n", __FILE__, __func__, __LINE__, c->core); ++ c->core = (read_c0_ebase() & 0x3ff) >> (fls(smp_num_siblings)-1); ++ printk("%s:%s[%d]%x\n", __FILE__, __func__, __LINE__, c->core); ++ + /* Assume GIC is present */ + change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | STATUSF_IP4 | + STATUSF_IP5 | STATUSF_IP6 | STATUSF_IP7); +Index: linux-4.9.37/arch/mips/ralink/mt7621.c +=================================================================== +--- linux-4.9.37.orig/arch/mips/ralink/mt7621.c ++++ linux-4.9.37/arch/mips/ralink/mt7621.c +@@ -18,6 +18,7 @@ + #include + #include + #include ++#include + + #include + +@@ -179,6 +180,58 @@ bool plat_cpu_core_present(int core) + return true; + } + ++#define LPS_PREC 8 ++/* ++* Re-calibration lpj(loop-per-jiffy). ++* (derived from kernel/calibrate.c) ++*/ ++static int udelay_recal(void) ++{ ++ unsigned int i, lpj = 0; ++ unsigned long ticks, loopbit; ++ int lps_precision = LPS_PREC; ++ ++ lpj = (1<<12); ++ ++ while ((lpj <<= 1) != 0) { ++ /* wait for "start of" clock tick */ ++ ticks = jiffies; ++ while (ticks == jiffies) ++ /* nothing */; ++ ++ /* Go .. */ ++ ticks = jiffies; ++ __delay(lpj); ++ ticks = jiffies - ticks; ++ if (ticks) ++ break; ++ } ++ ++ /* ++ * Do a binary approximation to get lpj set to ++ * equal one clock (up to lps_precision bits) ++ */ ++ lpj >>= 1; ++ loopbit = lpj; ++ while (lps_precision-- && (loopbit >>= 1)) { ++ lpj |= loopbit; ++ ticks = jiffies; ++ while (ticks == jiffies) ++ /* nothing */; ++ ticks = jiffies; ++ __delay(lpj); ++ if (jiffies != ticks) /* longer than 1 tick */ ++ lpj &= ~loopbit; ++ } ++ printk(KERN_INFO "%d CPUs re-calibrate udelay(lpj = %d)\n", NR_CPUS, lpj); ++ ++ for(i=0; i< NR_CPUS; i++) ++ cpu_data[i].udelay_val = lpj; ++ ++ return 0; ++} ++device_initcall(udelay_recal); ++ + void prom_soc_init(struct ralink_soc_info *soc_info) + { + void __iomem *sysc = (void __iomem *) KSEG1ADDR(MT7621_SYSC_BASE); +Index: linux-4.9.37/arch/mips/ralink/Kconfig +=================================================================== +--- linux-4.9.37.orig/arch/mips/ralink/Kconfig ++++ linux-4.9.37/arch/mips/ralink/Kconfig +@@ -56,6 +56,7 @@ choice + select COMMON_CLK + select CLKSRC_MIPS_GIC + select HW_HAS_PCI ++ select GENERIC_CLOCKEVENTS_BROADCAST + endchoice + + choice +Index: linux-4.9.37/arch/mips/ralink/timer-gic.c +=================================================================== +--- linux-4.9.37.orig/arch/mips/ralink/timer-gic.c ++++ linux-4.9.37/arch/mips/ralink/timer-gic.c +@@ -12,6 +12,7 @@ + #include + #include + #include ++#include + + #include "common.h" + +@@ -19,6 +20,8 @@ void __init plat_time_init(void) + { + ralink_of_remap(); + ++ mips_hpt_frequency = 880000000 / 2; ++ + of_clk_init(NULL); + clocksource_probe(); + } -- cgit v1.2.3