From patchwork Thu Aug 15 14:32:17 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Georgi Djakov X-Patchwork-Id: 2845190 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7DC819F271 for ; Thu, 15 Aug 2013 14:33:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CAA8720314 for ; Thu, 15 Aug 2013 14:32:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AD5F2030D for ; Thu, 15 Aug 2013 14:32:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757878Ab3HOOcM (ORCPT ); Thu, 15 Aug 2013 10:32:12 -0400 Received: from ns.mm-sol.com ([212.124.72.66]:52499 "EHLO extserv.mm-sol.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757696Ab3HOOcJ (ORCPT ); Thu, 15 Aug 2013 10:32:09 -0400 Received: from mms.int.mm-sol.com (unknown [172.18.0.3]) by extserv.mm-sol.com (Postfix) with ESMTPSA id C7A3CC698; Thu, 15 Aug 2013 17:32:07 +0300 (EEST) From: Georgi Djakov To: cjb@laptop.org Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Georgi Djakov , Venkat Gopalakrishnan , Asutosh Das , Sahitya Tummala Subject: [PATCH 2/5] mmc: sdhci: add quirk for slow interrupt clearance Date: Thu, 15 Aug 2013 17:32:17 +0300 Message-Id: <1376577140-2652-3-git-send-email-gdjakov@mm-sol.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1376577140-2652-1-git-send-email-gdjakov@mm-sol.com> References: <1376577140-2652-1-git-send-email-gdjakov@mm-sol.com> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-9.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Initial version of Qualcomm SDHC has a hardware issue. This patch adds a quirk SDHCI_QUIRK2_SLOW_INT_CLR to enable a workaround. Hardware issue: Slow interrupt clearance at 400KHz may cause host driver interrupt handler to be called twice. Software workaround: Add 40us delay in interrupt handler when operating at initialization frequency(400KHz). CC: Venkat Gopalakrishnan CC: Asutosh Das CC: Sahitya Tummala Signed-off-by: Georgi Djakov --- drivers/mmc/host/sdhci.c | 6 ++++++ include/linux/mmc/sdhci.h | 2 ++ 2 files changed, 8 insertions(+) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 57659fb..d3c9e59 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2460,12 +2460,18 @@ again: if (intmask & SDHCI_INT_CMD_MASK) { sdhci_writel(host, intmask & SDHCI_INT_CMD_MASK, SDHCI_INT_STATUS); + if ((host->quirks2 & SDHCI_QUIRK2_SLOW_INT_CLR) && + (host->clock <= 400000)) + udelay(40); sdhci_cmd_irq(host, intmask & SDHCI_INT_CMD_MASK); } if (intmask & SDHCI_INT_DATA_MASK) { sdhci_writel(host, intmask & SDHCI_INT_DATA_MASK, SDHCI_INT_STATUS); + if ((host->quirks2 & SDHCI_QUIRK2_SLOW_INT_CLR) && + (host->clock <= 400000)) + udelay(40); sdhci_data_irq(host, intmask & SDHCI_INT_DATA_MASK); } diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h index 3783f4c..afd7cdf 100644 --- a/include/linux/mmc/sdhci.h +++ b/include/linux/mmc/sdhci.h @@ -100,6 +100,8 @@ struct sdhci_host { #define SDHCI_QUIRK2_BROKEN_HOST_CONTROL (1<<5) /* Controller cannot de-assert Read/Write Transfer Active after transaction */ #define SDHCI_QUIRK2_RDWR_TX_ACTIVE_EOT (1<<6) +/* Controller clears interrupt slowly and IRQ handler may be called twice */ +#define SDHCI_QUIRK2_SLOW_INT_CLR (1<<7) int irq; /* Device IRQ */ void __iomem *ioaddr; /* Mapped address */