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From: Jun Nie <jun.nie@linaro.org>
To: ulf.hansson@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com,
	adrian.hunter@intel.com, linux-mmc@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: [PATCH 1/4] mmc: sdhci: Add delay after power off
Date: Mon,  2 Dec 2019 22:41:01 +0800	[thread overview]
Message-ID: <20191202144104.5069-2-jun.nie@linaro.org> (raw)
In-Reply-To: <20191202144104.5069-1-jun.nie@linaro.org>

Add delay after power off to ensure that full power cycle is
successful. Otherwise, some controllers, at lease for Hisilicon
eMMC controller, may not be unstable sometimes for full power
cycle operation.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
 drivers/mmc/host/sdhci.c | 7 +++++++
 drivers/mmc/host/sdhci.h | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3140fe2e5dba..a654f0aeb438 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1761,6 +1761,13 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
 		sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
 		if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
 			sdhci_runtime_pm_bus_off(host);
+
+		/*
+		 * Some controllers need an extra 100ms delay to secure
+		 * full power cycle is successful.
+		 */
+		if (host->quirks2 & SDHCI_QUIRK2_DELAY_AFTER_POWER_OFF)
+			msleep(100);
 	} else {
 		/*
 		 * Spec says that we should clear the power reg before setting
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0ed3e0eaef5f..0e6f97eaa796 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -482,6 +482,8 @@ struct sdhci_host {
  * block count.
  */
 #define SDHCI_QUIRK2_USE_32BIT_BLK_CNT			(1<<18)
+/* Controllers need an extra 100ms delay to make sure power off completely */
+#define SDHCI_QUIRK2_DELAY_AFTER_POWER_OFF		(1<<19)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
-- 
2.17.1


  reply	other threads:[~2019-12-02 14:41 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-02 14:41 [PATCH 0/4] mmc: Add sdhci workaround stability enhencement Jun Nie
2019-12-02 14:41 ` Jun Nie [this message]
2019-12-03  7:26   ` [PATCH 1/4] mmc: sdhci: Add delay after power off Adrian Hunter
2019-12-02 14:41 ` [PATCH 2/4] mmc: sdhci: dt: Add DMA boundary and HS400 properties Jun Nie
2019-12-13 23:01   ` Rob Herring
2019-12-17 14:56     ` Jun Nie
2019-12-02 14:41 ` [PATCH 3/4] mmc: sdhci: Set ctrl_hs400 value in dts Jun Nie
2019-12-03  7:52   ` Adrian Hunter
2019-12-02 14:41 ` [PATCH 4/4] mmc: sdhci: Add DMA memory boundary workaround Jun Nie
2019-12-02 17:52   ` Christoph Hellwig
2019-12-03  3:29     ` Jun Nie
2019-12-03  7:36       ` Christoph Hellwig
2019-12-04  6:00         ` Jun Nie
2019-12-04  7:14           ` Jisheng Zhang
2019-12-10  9:36             ` Ulf Hansson
2019-12-03  2:47   ` Jisheng Zhang
2019-12-03  3:33     ` Jun Nie
2019-12-03  9:05       ` Jisheng Zhang
2019-12-03  9:18         ` Christoph Hellwig
2019-12-03  9:49           ` Jisheng Zhang
2019-12-03 13:06             ` Christoph Hellwig
2019-12-04  7:11               ` Jisheng Zhang
2019-12-03  9:49         ` Jisheng Zhang
2019-12-03 13:04           ` Christoph Hellwig

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