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From:   Faiz Abbas <faiz_abbas@ti.com>
To:     <linux-kernel@vger.kernel.org>, <linux-mmc@vger.kernel.org>
CC:     <ulf.hansson@linaro.org>, <adrian.hunter@intel.com>,
        <faiz_abbas@ti.com>, <shawn.lin@rock-chips.com>
Subject: [PATCH 1/3] mmc: sdhci: Add Quirk to reset data lines after tuning
Date:   Mon, 30 Dec 2019 14:53:41 +0530
Message-ID: <20191230092343.30692-2-faiz_abbas@ti.com>
In-Reply-To: <20191230092343.30692-1-faiz_abbas@ti.com>
References: <20191230092343.30692-1-faiz_abbas@ti.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Some arasan controllers have data leftover in the buffer after tuning
procedure is complete which interferes with future data commands. Add a
quirk to reset the data after tuning is finished.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
---
 drivers/mmc/host/sdhci.c | 3 +++
 drivers/mmc/host/sdhci.h | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1b1c26da3fe0..e4b478efb560 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2316,6 +2316,9 @@ EXPORT_SYMBOL_GPL(sdhci_start_tuning);
 
 void sdhci_end_tuning(struct sdhci_host *host)
 {
+	if (host->quirks2 & SDHCI_QUIRK2_RESET_DATA_POST_TUNING)
+		sdhci_reset(host, SDHCI_RESET_DATA);
+
 	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 }
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index fe83ece6965b..28826124f7c3 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -484,6 +484,10 @@ struct sdhci_host {
  * block count.
  */
 #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
+/*
+ * Controller needs to reset data lines once tuning is complete
+ */
+#define SDHCI_QUIRK2_RESET_DATA_POST_TUNING		(1<<19)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
-- 
2.19.2