On 26/11/2018 04:49, Ryder Lee wrote: > On Fri, 2018-11-23 at 18:07 +0100, Matthias Brugger wrote: >> >> On 12/11/2018 02:28, Ryder Lee wrote: >>> The crash http://termbin.com/zitb is caused by the timer register >>> into system in early pahse during kernel boot, but the clock >>> sources didn't get ready at that time. >>> >>> A better way is to switch to use CLK_OF_DECLARE() in driver for things >>> that need them early, but this node is actually useless in MT7622. >>> So we drop it. >> >> I suppose the root cause is, that the driver doesn't check the error >> timer_of_init returned. >> >> Would you mind to test the following patch to see if this fixes the problem? >> >> --->8 >> From be91e56ed527261137335af340845eb3dd3dd33a Mon Sep 17 00:00:00 2001 >> From: Matthias Brugger <matthias.bgg@xxxxxxxxx> >> Date: Fri, 23 Nov 2018 17:04:08 +0100 >> Subject: [PATCH] clocksource/drivers/timer-mediatek: error out on probe defer >> >> If the clocks are not yet present, because they are loaded after >> the timer is initialized, we are unable to boot. >> Check if the return value of timer_of_init and return on EPROBE_DEFER. >> >> Error seen is: >> [ 0.008337] Failed to get clock for /timer@10004000 >> [ 0.013435] WARNING: CPU: 0 PID: 0 at ../drivers/clk/clk.c:3615 >> __clk_put+0xf0/0x120 >> [ 0.021453] Modules linked in: >> [ 0.024614] CPU: 0 PID: 0 Comm: swapper/0 Not tainted >> 4.20.0-rc1-00063-g2859d9abd7e8 #2 >> [ 0.032902] Hardware name: MediaTek MT7622 RFB1 board (DT) >> [ 0.038580] pstate: 20000085 (nzCv daIf -PAN -UAO) >> [ 0.043538] pc : __clk_put+0xf0/0x120 >> [ 0.047328] lr : clk_put+0xc/0x18 >> [ 0.050753] sp : ffff000009163ed0 >> [ 0.054178] x29: ffff000009163ed0 x28: 0000000041010018 >> [ 0.059676] x27: 0000000000000000 x26: 0000000000000000 >> [ 0.065174] x25: ffff0000090cb008 x24: ffff80001dfd7800 >> [ 0.070672] x23: ffff000008f934b8 x22: ffff80001dfdeae0 >> [ 0.076169] x21: ffff80001dfdeae0 x20: fffffffffffffdfb >> [ 0.081668] x19: ffff00000929ac40 x18: ffffffffffffffff >> [ 0.087166] x17: 0000000000000000 x16: 0000000000000000 >> [ 0.092664] x15: ffff0000091696c8 x14: ffff0000892cd70f >> [ 0.098162] x13: ffff0000092cd71d x12: ffff000009181348 >> [ 0.103661] x11: ffff000009181000 x10: 0000000005f5e0ff >> [ 0.109159] x9 : 0000000000000040 x8 : ffff000009181400 >> [ 0.114657] x7 : ffff80001c800270 x6 : 0000000000000000 >> [ 0.120155] x5 : ffff80001c800248 x4 : 0000000000000000 >> [ 0.125653] x3 : 0000000000000000 x2 : 0000000000000000 >> [ 0.131151] x1 : 0000000000000000 x0 : fffffffffffffdfb >> [ 0.136649] Call trace: >> [ 0.139175] __clk_put+0xf0/0x120 >> [ 0.142605] timer_of_cleanup+0x60/0x7c >> [ 0.146572] mtk_gpt_init+0x18c/0x1a0 >> [ 0.150359] timer_probe+0x74/0x10c >> [ 0.153969] time_init+0x14/0x44 >> [ 0.157307] start_kernel+0x29c/0x414 >> [ 0.161098] ---[ end trace c3137b005300b618 ]--- >> >> Fixes: a0858f937960 ("clocksource/drivers/timer-mediatek: Convert the driver to >> timer-of") >> Fixes: e3af677607d9 ("clocksource/drivers/timer-mediatek: Add support for system >> timer") >> Signed-off-by: Matthias Brugger <matthias.bgg@xxxxxxxxx> >> --- >> drivers/clocksource/timer-mediatek.c | 12 ++++++++++-- >> 1 file changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/clocksource/timer-mediatek.c >> b/drivers/clocksource/timer-mediatek.c >> index eb10321f8517..d40c77a65b08 100644 >> --- a/drivers/clocksource/timer-mediatek.c >> +++ b/drivers/clocksource/timer-mediatek.c >> @@ -276,8 +276,12 @@ static int __init mtk_syst_init(struct device_node *node) >> to.of_irq.handler = mtk_syst_handler; >> >> ret = timer_of_init(node, &to); >> - if (ret) >> + if (ret) { >> + if (ret == -EPROBE_DEFER) >> + return ret; >> + >> goto err; >> + } >> >> clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), >> TIMER_SYNC_TICKS, 0xffffffff); >> @@ -301,8 +305,12 @@ static int __init mtk_gpt_init(struct device_node *node) >> to.of_irq.handler = mtk_gpt_interrupt; >> >> ret = timer_of_init(node, &to); >> - if (ret) >> + if (ret) { >> + if (ret == -EPROBE_DEFER) >> + return ret; >> + >> goto err; >> + } >> >> /* Configure clock source */ >> mtk_gpt_setup(&to, TIMER_CLK_SRC, GPT_CTRL_OP_FREERUN); > > I tried this patch, but it didn't work. I think *_OF_DECLARE() is not > compatible with EPROBE_DEFER. > > I also found the similar discussion about this issue: > https://patchwork.kernel.org/patch/10580345/ > Got it. So from my research we would need to use CLK_OF_DECLARE_DRIVER for: mainpll (pll) syspll4_d16 (div) f10m_ref_sel (mux) infra_apxgpt_pd (gate) Anyway, as a quick fix we can delete the device node. I'll reword you commit message and I'll also reword commit message for 1/3 In the future please try to not put links into the commit message but explain what is happening. Regards, Matthias
