[PATCH v2 3/6] mmc: sdhci-of-esdhc: add erratum A-009204 support

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From: Yinbo Zhu <yinbo.zhu@xxxxxxx>

In the event of that any data error (like, IRQSTAT[DCE]) occurs
during an eSDHC data transaction where DMA is used for data
transfer to/from the system memory, setting the SYSCTL[RSTD]
register may cause a system hang. If software sets the register
SYSCTL[RSTD] to 1 for error recovery while DMA transferring is
not complete, eSDHC may hang the system bus. This happens because
the software register SYSCTL[RSTD] resets the DMA engine without
waiting for the completion of pending system transactions. This
erratum is to fix this issue.

Signed-off-by: Yinbo Zhu <yinbo.zhu@xxxxxxx>
---
Change in v2:
		 Do that within the driver's ->reset() fn.

 drivers/mmc/host/sdhci-of-esdhc.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 1ac1133..7e0eae8 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -694,6 +694,9 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask)
 	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
 	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
 
+	if (of_find_compatible_node(NULL, NULL, "fsl,p2020-esdhc"))
+		mdelay(5);
+
 	if (mask & SDHCI_RESET_ALL) {
 		val = sdhci_readl(host, ESDHC_TBCTL);
 		val &= ~ESDHC_TB_EN;
-- 
1.7.1





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