mmc: sdhci-of-esdhc: add erratum A-009204 support

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@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 04d7d95..57a4489 100644 (file)
--- 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;