This is a note to let you know that I've just added the patch titled ARM: rockchip: fix the CPU soft reset to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-rockchip-fix-the-cpu-soft-reset.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fe4407c0dc58215a7abfb7532740d79ddabe7a7a Mon Sep 17 00:00:00 2001 From: Caesar Wang <wxt@xxxxxxxxxxxxxx> Date: Tue, 9 Jun 2015 17:49:57 +0800 Subject: ARM: rockchip: fix the CPU soft reset From: Caesar Wang <wxt@xxxxxxxxxxxxxx> commit fe4407c0dc58215a7abfb7532740d79ddabe7a7a upstream. We need different orderings when turning a core on and turning a core off. In one case we need to assert reset before turning power off. In ther other case we need to turn power on and the deassert reset. In general, the correct flow is: CPU off: reset_control_assert regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), BIT(pd)) wait_for_power_domain_to_turn_off CPU on: regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0) wait_for_power_domain_to_turn_on reset_control_deassert This is needed for stressing CPU up/down, as per: cd /sys/devices/system/cpu/ for i in $(seq 10000); do echo "================= $i ============" for j in $(seq 100); do while [[ "$(cat cpu1/online)$(cat cpu2/online)$(cat cpu3/online)" != "000"" ]] echo 0 > cpu1/online echo 0 > cpu2/online echo 0 > cpu3/online done while [[ "$(cat cpu1/online)$(cat cpu2/online)$(cat cpu3/online)" != "111" ]]; do echo 1 > cpu1/online echo 1 > cpu2/online echo 1 > cpu3/online done done done The following is reproducable log: [34466.186812] PM: noirq suspend of devices complete after 0.669 msecs [34466.186824] Disabling non-boot CPUs ... [34466.187509] CPU1: shutdown [34466.188672] CPU2: shutdown [34473.736627] Kernel panic - not syncing:Watchdog detected hard LOCKUP on cpu 0 ....... or others similar log: ....... [ 4072.454453] CPU1: shutdown [ 4072.504436] CPU2: shutdown [ 4072.554426] CPU3: shutdown [ 4072.577827] CPU1: Booted secondary processor [ 4072.582611] CPU2: Booted secondary processor <hang> Tested by cpu up/down scripts, the results told us need delay more time before write the sram. The wait time is affected by many aspects (e.g: cpu frequency, bootrom frequency, sram frequency, bus speed, ...). Although the cpus other than cpu0 will write the sram, the speedy is no the same as cpu0, if the cpu0 early wake up, perhaps the other cpus can't startup. As we know, the cpu0 can wake up when the cpu1/2/3 write the 'sram+4/8' and send the sev. Anyway..... At the moment, 1ms delay will be happy work for cpu up/down scripts test. Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx> Reviewed-by: Doug Anderson <dianders@xxxxxxxxxxxx> Reviewed-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx> Fixes: 3ee851e212d0 ("ARM: rockchip: add basic smp support for rk3288") Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm/mach-rockchip/platsmp.c | 40 +++++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 18 deletions(-) --- a/arch/arm/mach-rockchip/platsmp.c +++ b/arch/arm/mach-rockchip/platsmp.c @@ -72,29 +72,22 @@ static struct reset_control *rockchip_ge static int pmu_set_power_domain(int pd, bool on) { u32 val = (on) ? 0 : BIT(pd); + struct reset_control *rstc = rockchip_get_core_reset(pd); int ret; + if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) { + pr_err("%s: could not get reset control for core %d\n", + __func__, pd); + return PTR_ERR(rstc); + } + /* * We need to soft reset the cpu when we turn off the cpu power domain, * or else the active processors might be stalled when the individual * processor is powered down. */ - if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) { - struct reset_control *rstc = rockchip_get_core_reset(pd); - - if (IS_ERR(rstc)) { - pr_err("%s: could not get reset control for core %d\n", - __func__, pd); - return PTR_ERR(rstc); - } - - if (on) - reset_control_deassert(rstc); - else - reset_control_assert(rstc); - - reset_control_put(rstc); - } + if (!IS_ERR(rstc) && !on) + reset_control_assert(rstc); ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); if (ret < 0) { @@ -112,6 +105,12 @@ static int pmu_set_power_domain(int pd, } } + if (!IS_ERR(rstc)) { + if (on) + reset_control_deassert(rstc); + reset_control_put(rstc); + } + return 0; } @@ -146,9 +145,14 @@ static int rockchip_boot_secondary(unsig * the mailbox: * sram_base_addr + 4: 0xdeadbeaf * sram_base_addr + 8: start address for pc + * The cpu0 need to wait the other cpus other than cpu0 entering + * the wfe state.The wait time is affected by many aspects. + * (e.g: cpu frequency, bootrom frequency, sram frequency, ...) * */ - udelay(10); - writel(virt_to_phys(secondary_startup), sram_base_addr + 8); + mdelay(1); /* ensure the cpus other than cpu0 to startup */ + + writel(virt_to_phys(rockchip_secondary_startup), + sram_base_addr + 8); writel(0xDEADBEAF, sram_base_addr + 4); dsb_sev(); } Patches currently in stable-queue which might be from wxt@xxxxxxxxxxxxxx are queue-4.2/arm-rockchip-fix-the-cpu-soft-reset.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html