From: Elad Nachman enachman@marvell.com
Each time SD/mmc phy is initialized, at times, in some of the attempts, phy fails to completes its initialization which results into timeout error. Per the HW spec, it is a pre-requisite to ensure a stable SD clock before a phy initialization is attempted.
Fixes: 06c8b667ff5b ("mmc: sdhci-xenon: Add support to PHYs of Marvell Xenon SDHC") Acked-by: Adrian Hunter adrian.hunter@intel.com Cc: stable@vger.kernel.org Signed-off-by: Elad Nachman enachman@marvell.com --- drivers/mmc/host/sdhci-xenon-phy.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/drivers/mmc/host/sdhci-xenon-phy.c b/drivers/mmc/host/sdhci-xenon-phy.c index 8cf3a375de65..c3096230a969 100644 --- a/drivers/mmc/host/sdhci-xenon-phy.c +++ b/drivers/mmc/host/sdhci-xenon-phy.c @@ -11,6 +11,7 @@ #include <linux/slab.h> #include <linux/delay.h> #include <linux/ktime.h> +#include <linux/iopoll.h> #include <linux/of_address.h>
#include "sdhci-pltfm.h" @@ -216,6 +217,19 @@ static int xenon_alloc_emmc_phy(struct sdhci_host *host) return 0; }
+static int xenon_check_stability_internal_clk(struct sdhci_host *host) +{ + u32 reg; + int err; + + err = read_poll_timeout(sdhci_readw, reg, reg & SDHCI_CLOCK_INT_STABLE, + 1100, 20000, false, host, SDHCI_CLOCK_CONTROL); + if (err) + dev_err(mmc_dev(host->mmc), "phy_init: Internal clock never stabilized.\n"); + + return err; +} + /* * eMMC 5.0/5.1 PHY init/re-init. * eMMC PHY init should be executed after: @@ -232,6 +246,11 @@ static int xenon_emmc_phy_init(struct sdhci_host *host) struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host); struct xenon_emmc_phy_regs *phy_regs = priv->emmc_phy_regs;
+ int ret = xenon_check_stability_internal_clk(host); + + if (ret) + return ret; + reg = sdhci_readl(host, phy_regs->timing_adj); reg |= XENON_PHY_INITIALIZAION; sdhci_writel(host, reg, phy_regs->timing_adj);