From patchwork Wed Aug 30 12:51:46 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vijay Viswanath X-Patchwork-Id: 9929527 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5BB2B60309 for ; Wed, 30 Aug 2017 12:54:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C1312856D for ; Wed, 30 Aug 2017 12:54:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4053128592; Wed, 30 Aug 2017 12:54:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C73482856D for ; Wed, 30 Aug 2017 12:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751707AbdH3Mwj (ORCPT ); Wed, 30 Aug 2017 08:52:39 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:42778 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751359AbdH3Mw2 (ORCPT ); Wed, 30 Aug 2017 08:52:28 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 3C2CC60731; Wed, 30 Aug 2017 12:52:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1504097548; bh=1VLtI1IO34QViqqr1+wunrR1ZI8YFun5gJPOnOj2ivo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hw8hYktC92LUKjEKOUv1GBI1P0P/J3SbpPo0x7dLgeLCDQDQpqzo0y6I93y99DgQU jyyT7e/p0OKYRST2Rx7PtwmulEjWji+zdSC6DzOQQoqQrhPXP3nDbrpxupWw9wezQn Se4rdWTEffinOcGuA8sqzWobhERgpPEvup89GXiw= Received: from hydcbspbld03.qualcomm.com (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: vviswana@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 3D6606072E; Wed, 30 Aug 2017 12:52:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1504097547; bh=1VLtI1IO34QViqqr1+wunrR1ZI8YFun5gJPOnOj2ivo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ozDRVOjcDdIhymcSPt0dU89PbZCfV/+Nio8WGCVAzuvAq6CC/0C+U/U/eRPDT0Mhe hSISEJthXgiJkobjRLj5FqV6QOhSQB/tJwAQmcMDcFi2+j5m49G3K9T968aIhn3+qk NLSBCacmutDeoDJBet9EAGNGID6DEsVCx3OcXnVc= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 3D6606072E Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=vviswana@codeaurora.org From: Vijay Viswanath To: adrian.hunter@intel.com, ulf.hansson@linaro.org, will.deacon@arm.com Cc: linux-arm-kernel@lists.infradead.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, asutoshd@codeaurora.org, stummala@codeaurora.org, riteshh@codeaurora.org, subhashj@codeaurora.org, Vijay Viswanath Subject: [PATCH v1 2/5] mmc: sdhci-msm: Fix HW issue with power IRQ handling during reset Date: Wed, 30 Aug 2017 18:21:46 +0530 Message-Id: <1504097509-58983-3-git-send-email-vviswana@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1504097509-58983-1-git-send-email-vviswana@codeaurora.org> References: <1504097509-58983-1-git-send-email-vviswana@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sahitya Tummala There is a rare scenario in HW, where the first clear pulse could be lost when the actual reset and clear/read of status register are happening at the same time. Fix this by retrying upto 10 times to ensure the status register gets cleared. Otherwise, this will lead to a spurious power IRQ which results in system instability. Signed-off-by: Sahitya Tummala Signed-off-by: Vijay Viswanath Acked-by: Adrian Hunter --- drivers/mmc/host/sdhci-msm.c | 46 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c index d636251..42a65ab 100644 --- a/drivers/mmc/host/sdhci-msm.c +++ b/drivers/mmc/host/sdhci-msm.c @@ -995,17 +995,52 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host, sdhci_msm_hs400(host, &mmc->ios); } -static void sdhci_msm_voltage_switch(struct sdhci_host *host) +static void sdhci_msm_dump_pwr_ctrl_regs(struct sdhci_host *host) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); + + pr_err("%s: PWRCTL_STATUS: 0x%08x | PWRCTL_MASK: 0x%08x | PWRCTL_CTL: 0x%08x\n", + mmc_hostname(host->mmc), + readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS), + readl_relaxed(msm_host->core_mem + CORE_PWRCTL_MASK), + readl_relaxed(msm_host->core_mem + CORE_PWRCTL_CTL)); +} + +static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); u32 irq_status, irq_ack = 0; + int retry = 10; irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS); irq_status &= INT_MASK; writel_relaxed(irq_status, msm_host->core_mem + CORE_PWRCTL_CLEAR); + /* + * There is a rare HW scenario where the first clear pulse could be + * lost when actual reset and clear/read of status register is + * happening at a time. Hence, retry for at least 10 times to make + * sure status register is cleared. Otherwise, this will result in + * a spurious power IRQ resulting in system instability. + */ + while (irq_status & readl_relaxed(msm_host->core_mem + + CORE_PWRCTL_STATUS)) { + if (retry == 0) { + pr_err("%s: Timedout clearing (0x%x) pwrctl status register\n", + mmc_hostname(host->mmc), irq_status); + sdhci_msm_dump_pwr_ctrl_regs(host); + WARN_ON(1); + break; + } + writel_relaxed(irq_status, + msm_host->core_mem + CORE_PWRCTL_CLEAR); + retry--; + udelay(10); + } + if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) irq_ack |= CORE_PWRCTL_BUS_SUCCESS; if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) @@ -1017,13 +1052,17 @@ static void sdhci_msm_voltage_switch(struct sdhci_host *host) * switches are handled by the sdhci core, so just report success. */ writel_relaxed(irq_ack, msm_host->core_mem + CORE_PWRCTL_CTL); + + pr_debug("%s: %s: Handled IRQ(%d), irq_status=0x%x, ack=0x%x\n", + mmc_hostname(msm_host->mmc), __func__, irq, irq_status, + irq_ack); } static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data) { struct sdhci_host *host = (struct sdhci_host *)data; - sdhci_msm_voltage_switch(host); + sdhci_msm_handle_pwr_irq(host, irq); return IRQ_HANDLED; } @@ -1106,7 +1145,6 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock) .get_max_clock = sdhci_msm_get_max_clock, .set_bus_width = sdhci_set_bus_width, .set_uhs_signaling = sdhci_msm_set_uhs_signaling, - .voltage_switch = sdhci_msm_voltage_switch, }; static const struct sdhci_pltfm_data sdhci_msm_pdata = { @@ -1257,7 +1295,7 @@ static int sdhci_msm_probe(struct platform_device *pdev) * acknowledged. Otherwise power irq interrupt handler would be * fired prematurely. */ - sdhci_msm_voltage_switch(host); + sdhci_msm_handle_pwr_irq(host, 0); /* * Ensure that above writes are propogated before interrupt enablement