From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [RESEND PATCH] mmc: sdhci: fix wakeup configuration Date: Fri, 13 May 2016 15:46:42 +0300 Message-ID: <5735CCB2.6020503@intel.com> References: <1463131622-6380-1-git-send-email-ludovic.desroches@atmel.com> <5735BC71.4020500@intel.com> <20160513121932.GS27024@odux.rfo.atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:53978 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751139AbcEMMui (ORCPT ); Fri, 13 May 2016 08:50:38 -0400 In-Reply-To: <20160513121932.GS27024@odux.rfo.atmel.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ludovic Desroches Cc: ulf.hansson@linaro.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, nicolas.ferre@atmel.com, Kevin Liu , Jialing Fu , Jisheng Zhang On 13/05/16 15:19, Ludovic Desroches wrote: > On Fri, May 13, 2016 at 02:37:21PM +0300, Adrian Hunter wrote: >> + cc some Marvell people because they added this code >> >> On 13/05/16 12:27, Ludovic Desroches wrote: >>> Activating wakeup event is not enough to get a wakeup signal. The >>> corresponding events have to be enabled in the Interrupt Status Enable >>> Register too. >> >> That seems to follow the specification. Did you find that you actually >> needed this change to get it to work? >> > > Yes, I din't wake up on card event without this patch. > >>> >>> Signed-off-by: Ludovic Desroches >>> --- >>> Hi, >>> >>> I just updated sdhci_enable_irq_wakeups() not sdhci_disable_irq_wakeups() >>> because I don't think it is necessary to configure SDHCI_INT_ENABLE at this >>> step, it will be done with sdhci_init() or sdhci_enable_card_detection(). >> >> OK, but that should be in the commit message and commented in the code too. > > I'll add it. > >> >>> >>> While I was writing this patch, several questions came to my mind: >>> - Is the naming correct? wakeup signal is not an irq. 'enable_irq_wakeups' can >>> be a bit confusing. >> >> I don't support renaming things unless the names are really really bad. >> These names are OK. >> >>> - If we want to wakeup from irq, we may have to set SDHCI_INT_ENABLE and >>> SDHCI_SIGNAL_ENABLE and not rely on a previous configuration, isn't it? >> >> I imagine the card interrupt will occur when it is enabled. I don't know >> about card insert / remove. >> >> What works for you? >> > > I only use wakeup events and not irqs in system PM (patches for > sdhci-of-at91 are not sent yet, I am waiting for the inclusion of other > patches). It doesn't hurt to say in the commit message what driver or hardware needed the change. > > What I mean is that if we want to wake up from irqs, it could be safer and > clearer to set explicitely SDHCI_INT_ENABLE and SDHCI_SIGNAL_ENABLE in > sdhci_enable_irq_wakeups(). It is just a thought and not needed for this > patch. > >>> >>> Regards >>> >>> Ludovic >>> >>> drivers/mmc/host/sdhci.c | 26 ++++++++++++++++++-------- >>> 1 file changed, 18 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >>> index b284924..6fc69ed 100644 >>> --- a/drivers/mmc/host/sdhci.c >>> +++ b/drivers/mmc/host/sdhci.c >>> @@ -2638,18 +2638,28 @@ static irqreturn_t sdhci_thread_irq(int irq, void *dev_id) >>> \*****************************************************************************/ >>> >>> #ifdef CONFIG_PM >>> +/* >>> + * To enable wakeup events, the corresponding events have to be enabled in >>> + * the Interrupt Status Enable register too. See 'Table 1-6: Wakeup Signal >>> + * Table' in the SD Host Controller Standard Specification. >>> + */ >>> void sdhci_enable_irq_wakeups(struct sdhci_host *host) >>> { >>> - u8 val; >>> - u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE >>> - | SDHCI_WAKE_ON_INT; >>> + u8 wakeup_val; >>> + u8 wakeup_mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE | >>> + SDHCI_WAKE_ON_INT; >> >> Please don't rename variables, or tidy-up code that you are not changing. >> > > I thought it will be better to have wakeup_val and irq_val instead of > val and irq_val. That's why I renamed it while introducing irq_val. val and irq_val are fine. > >>> + u32 irq_val = SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE | >>> + SDHCI_INT_CARD_INT; >>> >>> - val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL); >>> - val |= mask ; >> >> These 2 line are actually unchanged. >> >>> + wakeup_val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL); >>> + wakeup_val |= wakeup_mask; >>> /* Avoid fake wake up */ >>> - if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) >>> - val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE); >>> - sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL); >>> + if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) { >>> + wakeup_val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE); >>> + irq_val &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE); >>> + } >>> + sdhci_writeb(host, wakeup_val, SDHCI_WAKE_UP_CONTROL); >>> + sdhci_writel(host, irq_val, SDHCI_INT_ENABLE); >>> } >>> EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups); >>> >>> >> >