Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758640Ab3HOOdB (ORCPT ); Thu, 15 Aug 2013 10:33:01 -0400 Received: from ns.mm-sol.com ([212.124.72.66]:52475 "EHLO extserv.mm-sol.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757088Ab3HOOcF (ORCPT ); Thu, 15 Aug 2013 10:32:05 -0400 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 1/5] mmc: sdhci: add quirk for R/W Transfer Active EOT Date: Thu, 15 Aug 2013 17:32:16 +0300 Message-Id: <1376577140-2652-2-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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1946 Lines: 53 Initial version of Qualcomm SDHC has a hardware issue. This patch adds a quirk SDHCI_QUIRK2_RDWR_TX_ACTIVE_EOT to enable a workaround. Hardware issue: Read Transfer Active/ Write Transfer Active may be not de-asserted after end of transaction. Software workaround: Set Software Reset for DAT line in Software Reset Register (Bit 2). CC: Venkat Gopalakrishnan CC: Asutosh Das CC: Sahitya Tummala Signed-off-by: Georgi Djakov --- drivers/mmc/host/sdhci.c | 3 +++ include/linux/mmc/sdhci.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index a78bd4f..57659fb 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2155,6 +2155,9 @@ static void sdhci_tasklet_finish(unsigned long param) controllers do not like that. */ sdhci_reset(host, SDHCI_RESET_CMD); sdhci_reset(host, SDHCI_RESET_DATA); + } else { + if (host->quirks2 & SDHCI_QUIRK2_RDWR_TX_ACTIVE_EOT) + sdhci_reset(host, SDHCI_RESET_DATA); } host->mrq = NULL; diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h index e3c6a74..3783f4c 100644 --- a/include/linux/mmc/sdhci.h +++ b/include/linux/mmc/sdhci.h @@ -98,6 +98,8 @@ struct sdhci_host { #define SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON (1<<4) /* Controller has a non-standard host control register */ #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) int irq; /* Device IRQ */ void __iomem *ioaddr; /* Mapped address */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/