On Wed, 7 Feb 2024 at 18:04, Elad Nachman <[email protected]> wrote:
>
> From: Elad Nachman <[email protected]>
>
> 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.
>
> Signed-off-by: Elad Nachman <[email protected]>
> ---
> drivers/mmc/host/sdhci-xenon-phy.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-xenon-phy.c b/drivers/mmc/host/sdhci-xenon-phy.c
> index 8cf3a375de65..4e99197b62c3 100644
> --- a/drivers/mmc/host/sdhci-xenon-phy.c
> +++ b/drivers/mmc/host/sdhci-xenon-phy.c
> @@ -216,6 +216,24 @@ 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;
> + ktime_t timeout;
> +
> + /* Wait max 20 ms */
> + timeout = ktime_add_ms(ktime_get(), 20);
> + while (!((reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> + & SDHCI_CLOCK_INT_STABLE)) {
> + if (ktime_after(ktime_get(), timeout)) {
> + dev_err(mmc_dev(host->mmc), "phy_init: Internal clock never stabilized.\n");
> + return -ETIMEDOUT;
> + }
> + usleep_range(900, 1100);
> + }
> + return 0;
Please convert the above into readx_poll_timeout() or similar.
> +}
> +
> /*
> * eMMC 5.0/5.1 PHY init/re-init.
> * eMMC PHY init should be executed after:
> @@ -232,6 +250,11 @@ 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);
Kind regards
Uffe