[PATCH 5.4 191/191] mmc: sdhci-of-esdhc: re-implement erratum A-009204 workaround

[Greg Kroah-Hartman]

From: Yangbo Lu <yangbo.lu@xxxxxxx>

[ Upstream commit f667216c5c7c967c3e568cdddefb51fe606bfe26 ]

The erratum A-009204 workaround patch was reverted because of
incorrect implementation.

8b6dc6b mmc: sdhci-of-esdhc: Revert "mmc: sdhci-of-esdhc: add
        erratum A-009204 support"

This patch is to re-implement the workaround (add a 5 ms delay
before setting SYSCTL[RSTD] to make sure all the DMA transfers
are finished).

Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx>
Link: https://lore.kernel.org/r/20191219032335.26528-1-yangbo.lu@xxxxxxx
Fixes: 5dd195522562 ("mmc: sdhci-of-esdhc: add erratum A-009204 support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/mmc/host/sdhci-of-esdhc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 14f0cb7fa374..fcfb50f84c8b 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -80,6 +80,7 @@ struct sdhci_esdhc {
 	bool quirk_tuning_erratum_type1;
 	bool quirk_tuning_erratum_type2;
 	bool quirk_ignore_data_inhibit;
+	bool quirk_delay_before_data_reset;
 	bool in_sw_tuning;
 	unsigned int peripheral_clock;
 	const struct esdhc_clk_fixup *clk_fixup;
@@ -735,6 +736,11 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask)
 	struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
 	u32 val;
 
+	if (esdhc->quirk_delay_before_data_reset &&
+	    (mask & SDHCI_RESET_DATA) &&
+	    (host->flags & SDHCI_REQ_USE_DMA))
+		mdelay(5);
+
 	sdhci_reset(host, mask);
 
 	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
@@ -1197,6 +1203,10 @@ static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
 	if (match)
 		esdhc->clk_fixup = match->data;
 	np = pdev->dev.of_node;
+
+	if (of_device_is_compatible(np, "fsl,p2020-esdhc"))
+		esdhc->quirk_delay_before_data_reset = true;
+
 	clk = of_clk_get(np, 0);
 	if (!IS_ERR(clk)) {
 		/*
-- 
2.20.1