From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH v2 1/5] clocksource: mediatek: do not enable GPT_CLK_EVT when setup Date: Thu, 13 Aug 2015 10:35:16 +0200 Message-ID: <55CC56C4.8080201@linaro.org> References: <1437552878-3684-1-git-send-email-yingjoe.chen@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1437552878-3684-1-git-send-email-yingjoe.chen@mediatek.com> Sender: linux-kernel-owner@vger.kernel.org To: Yingjoe Chen , Daniel Kurtz , Stephen Boyd , Thomas Gleixner Cc: James Liao , Russell King , srv_heupstream , Arnd Bergmann , "open list:OPEN FIRMWARE AND..." , Catalin Marinas , Michael Turquette , "linux-kernel@vger.kernel.org" , Olof Johansson , Rob Herring , linux-mediatek@lists.infradead.org, Sascha Hauer , Matthias Brugger , linux-clk@vger.kernel.org, "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On 07/22/2015 10:14 AM, Yingjoe Chen wrote: > Spurious mtk timer interrupt is noticed at boot and cause kernel > crash. It seems if GPT is enabled, it will latch irq status even > when its IRQ is disabled. When irq is enabled afterward, we see > spurious interrupt. > Change init flow to only enable GPT_CLK_SRC at mtk_timer_init. > > Acked-by: Matthias Brugger > Reviewed-by: Daniel Kurtz > Signed-off-by: Yingjoe Chen > --- > > Update to my patch [1], added __init as Daniel suggest. This is the > only patch that need to change in that series, so I only sent this on= e. > > http://lists.infradead.org/pipermail/linux-mediatek/2015-July/001545.= html > > drivers/clocksource/mtk_timer.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/clocksource/mtk_timer.c b/drivers/clocksource/mt= k_timer.c > index 68ab423..2ba5b66 100644 > --- a/drivers/clocksource/mtk_timer.c > +++ b/drivers/clocksource/mtk_timer.c > @@ -156,9 +156,11 @@ static void mtk_timer_global_reset(struct mtk_cl= ock_event_device *evt) > writel(0x3f, evt->gpt_base + GPT_IRQ_ACK_REG); > } > > -static void > -mtk_timer_setup(struct mtk_clock_event_device *evt, u8 timer, u8 opt= ion) > +static void __init mtk_timer_setup(struct mtk_clock_event_device *ev= t, > + u8 timer, u8 option, bool enable) > { > + u32 val; > + > writel(TIMER_CTRL_CLEAR | TIMER_CTRL_DISABLE, > evt->gpt_base + TIMER_CTRL_REG(timer)); > > @@ -167,8 +169,10 @@ mtk_timer_setup(struct mtk_clock_event_device *e= vt, u8 timer, u8 option) > > writel(0x0, evt->gpt_base + TIMER_CMP_REG(timer)); > > - writel(TIMER_CTRL_OP(option) | TIMER_CTRL_ENABLE, > - evt->gpt_base + TIMER_CTRL_REG(timer)); > + val =3D TIMER_CTRL_OP(option); > + if (enable) > + val |=3D TIMER_CTRL_ENABLE; > + writel(val, evt->gpt_base + TIMER_CTRL_REG(timer)); Instead of the 'enable' new option, I prefer a test with 'timer' with a= =20 comment: /* * the timer hw is broken in that way ... bla bla, so we only * enable the clocksource ... */ if (timer =3D=3D GPT_CLK_SRC) val |=3D TIMER_CTRL_ENABLE; That said, can you have a look at commit 1096be08 ? "clockevents: sun5i: Fix setup_irq init sequence" first and check if moving the interrupt request after the=20 clockevents_config_and_register could fix your issue. > } > > static void mtk_timer_enable_irq(struct mtk_clock_event_device *evt= , u8 timer) > @@ -235,12 +239,12 @@ static void __init mtk_timer_init(struct device= _node *node) > evt->ticks_per_jiffy =3D DIV_ROUND_UP(rate, HZ); > > /* Configure clock source */ > - mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN); > + mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN, true); > clocksource_mmio_init(evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC), > node->name, rate, 300, 32, clocksource_mmio_readl_up); > > /* Configure clock event */ > - mtk_timer_setup(evt, GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT); > + mtk_timer_setup(evt, GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT, false); > clockevents_config_and_register(&evt->dev, rate, 0x3, > 0xffffffff); --=20 Linaro.org =E2=94=82 Open source software fo= r ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog