The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 8e9f25a290ae0016353c9ea13314c95fb3207812 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024030400-debate-conclude-99e5@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: 8e9f25a290ae ("mmc: sdhci-xenon: fix PHY init clock stability") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8e9f25a290ae0016353c9ea13314c95fb3207812 Mon Sep 17 00:00:00 2001 From: Elad Nachman <enachman@xxxxxxxxxxx> Date: Thu, 22 Feb 2024 22:09:30 +0200 Subject: [PATCH] mmc: sdhci-xenon: fix PHY init clock stability 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@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Elad Nachman <enachman@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20240222200930.1277665-1-enachman@xxxxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> 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);
