From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10D48C6778C for ; Wed, 4 Jul 2018 11:34:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9B4920899 for ; Wed, 4 Jul 2018 11:34:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9B4920899 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934182AbeGDLeH (ORCPT ); Wed, 4 Jul 2018 07:34:07 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:35814 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932594AbeGDLeE (ORCPT ); Wed, 4 Jul 2018 07:34:04 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5E5CC18A; Wed, 4 Jul 2018 04:34:04 -0700 (PDT) Received: from [10.1.206.75] (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 157CA3F5AD; Wed, 4 Jul 2018 04:34:02 -0700 (PDT) Subject: Re: [PATCH v2 1/1] mmc: sunxi: Disable irq during pm_suspend To: Ulf Hansson , Stefan Mavrodiev Cc: Maxime Ripard , Chen-Yu Tsai , "open list:MULTIMEDIA CARD (MMC), SECURE DIGITAL (SD) AND..." , "moderated list:ARM/Allwinner sunXi SoC support" , open list References: <1530685741-20604-1-git-send-email-stefan@olimex.com> From: Marc Zyngier Organization: ARM Ltd Message-ID: <9b8f30fd-12aa-46ba-ced9-aed38ada0059@arm.com> Date: Wed, 4 Jul 2018 12:34:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/07/18 11:50, Ulf Hansson wrote: > + Marc > > On 4 July 2018 at 08:28, Stefan Mavrodiev wrote: >> When mmc host controller enters suspend state, the clocks are >> disabled, but irqs are not. For some reason the irqchip emits >> false interrupts, which causes system lock loop. >> >> Debug log is: >> ... >> sunxi-mmc 1c11000.mmc: setting clk to 52000000, rounded 51200000 >> sunxi-mmc 1c11000.mmc: enabling the clock >> sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> sunxi-mmc 1c11000.mmc: cmd 6(80000146) arg 3210101 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> mmc1: new DDR MMC card at address 0001 >> mmcblk1: mmc1:0001 AGND3R 14.6 GiB >> mmcblk1boot0: mmc1:0001 AGND3R partition 1 4.00 MiB >> mmcblk1boot1: mmc1:0001 AGND3R partition 2 4.00 MiB >> sunxi-mmc 1c11000.mmc: cmd 18(80003352) arg 0 ie 0x0000fbc2 len 409 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00004000 idi 00000002 >> mmcblk1: p1 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> and so on... >> >> This issue apears on eMMC cards, routed on MMC2 slot. The patch is >> tested with A20-OLinuXino-MICRO/LIME/LIME2 boards. >> >> Fixes: 9a8e1e8cc2c0 ("mmc: sunxi: Add runtime_pm support") >> Signed-off-by: Stefan Mavrodiev >> --- >> Changes in v2: >> - Add comment why disable_irq() is necessary >> >> --- >> drivers/mmc/host/sunxi-mmc.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c >> index e747259..8e7f3e3 100644 >> --- a/drivers/mmc/host/sunxi-mmc.c >> +++ b/drivers/mmc/host/sunxi-mmc.c >> @@ -1446,6 +1446,7 @@ static int sunxi_mmc_runtime_resume(struct device *dev) >> sunxi_mmc_init_host(host); >> sunxi_mmc_set_bus_width(host, mmc->ios.bus_width); >> sunxi_mmc_set_clk(host, &mmc->ios); >> + enable_irq(host->irq); >> >> return 0; >> } >> @@ -1455,6 +1456,12 @@ static int sunxi_mmc_runtime_suspend(struct device *dev) >> struct mmc_host *mmc = dev_get_drvdata(dev); >> struct sunxi_mmc_host *host = mmc_priv(mmc); >> >> + /* >> + * When clocks are off, it's possible receiving >> + * fake interrupts, which will stall the system. >> + * Disabling the irq will prevent this. >> + */ >> + disable_irq(host->irq); > > No, this doesn't work for shared IRQs. Well, in this case, it does work, because that interrupt line cannot be shared with anything else, if I understand how the SoC is wired: each MMC controller has a dedicated interrupt line to the GIC, and it isn't shared with anything (that's on the A20 though, and I don't know about other SoCs integrating the same IP). > >> sunxi_mmc_reset_host(host); >> sunxi_mmc_disable(host); >> >> -- >> 2.7.4 >> > > The only option today is to use free_irq() in runtime suspend and then > re-request the irq to re-install the handler at runtime resume. > > That's not an optimal solution, which is pointed out in the below > discussion as well. Moreover, it has also turned out using free_irq() > is also problematic in cases threaded handlers are used. > > Here's the link to the discussion, it's not the only one I know of, so > this is common problem. > https://lkml.org/lkml/2016/1/28/213 > > Care to have a hack on the "common" solution, which in principle means > adding APIs to genirq that can disable/enable handlers from being > called, rather than the entire IRQ line. That doesn't work. You still end-up with a screaming interrupt, and you will still spend 100% of your time in interrupt context for nothing. Eventually, the kernel will have enough (the /other/ shared handlers returning IRQ_NONE all the time), and will forcefully kill that particular interrupt interrupt line, meaning you end-up in the same situation of having the line disabled for all the users of that interrupt line. Except that now, it is disabled forever. A better fix would be to kill the interrupt generation at the source (the MMC controller in this particular case) when suspending. Thanks, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v2 1/1] mmc: sunxi: Disable irq during pm_suspend Date: Wed, 4 Jul 2018 12:34:01 +0100 Message-ID: <9b8f30fd-12aa-46ba-ced9-aed38ada0059@arm.com> References: <1530685741-20604-1-git-send-email-stefan@olimex.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson , Stefan Mavrodiev Cc: Maxime Ripard , Chen-Yu Tsai , "open list:MULTIMEDIA CARD (MMC), SECURE DIGITAL (SD) AND..." , "moderated list:ARM/Allwinner sunXi SoC support" , open list List-Id: linux-mmc@vger.kernel.org On 04/07/18 11:50, Ulf Hansson wrote: > + Marc > > On 4 July 2018 at 08:28, Stefan Mavrodiev wrote: >> When mmc host controller enters suspend state, the clocks are >> disabled, but irqs are not. For some reason the irqchip emits >> false interrupts, which causes system lock loop. >> >> Debug log is: >> ... >> sunxi-mmc 1c11000.mmc: setting clk to 52000000, rounded 51200000 >> sunxi-mmc 1c11000.mmc: enabling the clock >> sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> sunxi-mmc 1c11000.mmc: cmd 6(80000146) arg 3210101 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> mmc1: new DDR MMC card at address 0001 >> mmcblk1: mmc1:0001 AGND3R 14.6 GiB >> mmcblk1boot0: mmc1:0001 AGND3R partition 1 4.00 MiB >> mmcblk1boot1: mmc1:0001 AGND3R partition 2 4.00 MiB >> sunxi-mmc 1c11000.mmc: cmd 18(80003352) arg 0 ie 0x0000fbc2 len 409 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00004000 idi 00000002 >> mmcblk1: p1 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> and so on... >> >> This issue apears on eMMC cards, routed on MMC2 slot. The patch is >> tested with A20-OLinuXino-MICRO/LIME/LIME2 boards. >> >> Fixes: 9a8e1e8cc2c0 ("mmc: sunxi: Add runtime_pm support") >> Signed-off-by: Stefan Mavrodiev >> --- >> Changes in v2: >> - Add comment why disable_irq() is necessary >> >> --- >> drivers/mmc/host/sunxi-mmc.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c >> index e747259..8e7f3e3 100644 >> --- a/drivers/mmc/host/sunxi-mmc.c >> +++ b/drivers/mmc/host/sunxi-mmc.c >> @@ -1446,6 +1446,7 @@ static int sunxi_mmc_runtime_resume(struct device *dev) >> sunxi_mmc_init_host(host); >> sunxi_mmc_set_bus_width(host, mmc->ios.bus_width); >> sunxi_mmc_set_clk(host, &mmc->ios); >> + enable_irq(host->irq); >> >> return 0; >> } >> @@ -1455,6 +1456,12 @@ static int sunxi_mmc_runtime_suspend(struct device *dev) >> struct mmc_host *mmc = dev_get_drvdata(dev); >> struct sunxi_mmc_host *host = mmc_priv(mmc); >> >> + /* >> + * When clocks are off, it's possible receiving >> + * fake interrupts, which will stall the system. >> + * Disabling the irq will prevent this. >> + */ >> + disable_irq(host->irq); > > No, this doesn't work for shared IRQs. Well, in this case, it does work, because that interrupt line cannot be shared with anything else, if I understand how the SoC is wired: each MMC controller has a dedicated interrupt line to the GIC, and it isn't shared with anything (that's on the A20 though, and I don't know about other SoCs integrating the same IP). > >> sunxi_mmc_reset_host(host); >> sunxi_mmc_disable(host); >> >> -- >> 2.7.4 >> > > The only option today is to use free_irq() in runtime suspend and then > re-request the irq to re-install the handler at runtime resume. > > That's not an optimal solution, which is pointed out in the below > discussion as well. Moreover, it has also turned out using free_irq() > is also problematic in cases threaded handlers are used. > > Here's the link to the discussion, it's not the only one I know of, so > this is common problem. > https://lkml.org/lkml/2016/1/28/213 > > Care to have a hack on the "common" solution, which in principle means > adding APIs to genirq that can disable/enable handlers from being > called, rather than the entire IRQ line. That doesn't work. You still end-up with a screaming interrupt, and you will still spend 100% of your time in interrupt context for nothing. Eventually, the kernel will have enough (the /other/ shared handlers returning IRQ_NONE all the time), and will forcefully kill that particular interrupt interrupt line, meaning you end-up in the same situation of having the line disabled for all the users of that interrupt line. Except that now, it is disabled forever. A better fix would be to kill the interrupt generation at the source (the MMC controller in this particular case) when suspending. Thanks, M. -- Jazz is not dead. It just smells funny... From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Wed, 4 Jul 2018 12:34:01 +0100 Subject: [PATCH v2 1/1] mmc: sunxi: Disable irq during pm_suspend In-Reply-To: References: <1530685741-20604-1-git-send-email-stefan@olimex.com> Message-ID: <9b8f30fd-12aa-46ba-ced9-aed38ada0059@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/07/18 11:50, Ulf Hansson wrote: > + Marc > > On 4 July 2018 at 08:28, Stefan Mavrodiev wrote: >> When mmc host controller enters suspend state, the clocks are >> disabled, but irqs are not. For some reason the irqchip emits >> false interrupts, which causes system lock loop. >> >> Debug log is: >> ... >> sunxi-mmc 1c11000.mmc: setting clk to 52000000, rounded 51200000 >> sunxi-mmc 1c11000.mmc: enabling the clock >> sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> sunxi-mmc 1c11000.mmc: cmd 6(80000146) arg 3210101 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000 >> mmc1: new DDR MMC card at address 0001 >> mmcblk1: mmc1:0001 AGND3R 14.6 GiB >> mmcblk1boot0: mmc1:0001 AGND3R partition 1 4.00 MiB >> mmcblk1boot1: mmc1:0001 AGND3R partition 2 4.00 MiB >> sunxi-mmc 1c11000.mmc: cmd 18(80003352) arg 0 ie 0x0000fbc2 len 409 >> sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00004000 idi 00000002 >> mmcblk1: p1 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000 >> and so on... >> >> This issue apears on eMMC cards, routed on MMC2 slot. The patch is >> tested with A20-OLinuXino-MICRO/LIME/LIME2 boards. >> >> Fixes: 9a8e1e8cc2c0 ("mmc: sunxi: Add runtime_pm support") >> Signed-off-by: Stefan Mavrodiev >> --- >> Changes in v2: >> - Add comment why disable_irq() is necessary >> >> --- >> drivers/mmc/host/sunxi-mmc.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c >> index e747259..8e7f3e3 100644 >> --- a/drivers/mmc/host/sunxi-mmc.c >> +++ b/drivers/mmc/host/sunxi-mmc.c >> @@ -1446,6 +1446,7 @@ static int sunxi_mmc_runtime_resume(struct device *dev) >> sunxi_mmc_init_host(host); >> sunxi_mmc_set_bus_width(host, mmc->ios.bus_width); >> sunxi_mmc_set_clk(host, &mmc->ios); >> + enable_irq(host->irq); >> >> return 0; >> } >> @@ -1455,6 +1456,12 @@ static int sunxi_mmc_runtime_suspend(struct device *dev) >> struct mmc_host *mmc = dev_get_drvdata(dev); >> struct sunxi_mmc_host *host = mmc_priv(mmc); >> >> + /* >> + * When clocks are off, it's possible receiving >> + * fake interrupts, which will stall the system. >> + * Disabling the irq will prevent this. >> + */ >> + disable_irq(host->irq); > > No, this doesn't work for shared IRQs. Well, in this case, it does work, because that interrupt line cannot be shared with anything else, if I understand how the SoC is wired: each MMC controller has a dedicated interrupt line to the GIC, and it isn't shared with anything (that's on the A20 though, and I don't know about other SoCs integrating the same IP). > >> sunxi_mmc_reset_host(host); >> sunxi_mmc_disable(host); >> >> -- >> 2.7.4 >> > > The only option today is to use free_irq() in runtime suspend and then > re-request the irq to re-install the handler at runtime resume. > > That's not an optimal solution, which is pointed out in the below > discussion as well. Moreover, it has also turned out using free_irq() > is also problematic in cases threaded handlers are used. > > Here's the link to the discussion, it's not the only one I know of, so > this is common problem. > https://lkml.org/lkml/2016/1/28/213 > > Care to have a hack on the "common" solution, which in principle means > adding APIs to genirq that can disable/enable handlers from being > called, rather than the entire IRQ line. That doesn't work. You still end-up with a screaming interrupt, and you will still spend 100% of your time in interrupt context for nothing. Eventually, the kernel will have enough (the /other/ shared handlers returning IRQ_NONE all the time), and will forcefully kill that particular interrupt interrupt line, meaning you end-up in the same situation of having the line disabled for all the users of that interrupt line. Except that now, it is disabled forever. A better fix would be to kill the interrupt generation at the source (the MMC controller in this particular case) when suspending. Thanks, M. -- Jazz is not dead. It just smells funny...