Since commit 5a52c5701a67 ("mmc: core: Fix host controller programming for fixed driver type"), the eMMC driver strength is passed directly to mmc_set_driver_type(), which propagates the value through ios.drv_type all the way to sdhci_set_ios(). For value 4, SDHCI correctly warns: mmc2: invalid driver type, default to driver type B The host driver type has no effect on this controller: esdhc_writew_le() never programs the driver-type field of SDHCI_HOST_CONTROL2. Hook set_ios() and force drv_type to the always-valid Type B, so that SDHCI never sees an unsupported value. Tested on i.MX8MP (usdhc3, eMMC in HS400) with `fixed-emmc-driver-type = <4>`: the warning is gone and the HS_TIMING register contains 0x43 as expected. Fixes: 5a52c5701a67 ("mmc: core: Fix host controller programming for fixed driver type") Link: https://lore.kernel.org/all/20260926122908.866-1-ian.ray@gehealthcare.com/ Cc: stable@vger.kernel.org Suggested-by: Adrian Hunter Signed-off-by: Ian Ray --- v2 -> v3: Force drv_type to Type B unconditionally; hook set_ios() for all esdhc variants, not only usdhc (since the driver-type field is ignored in all variants); reword comments. v1 -> v2: Move fix from mmc core to sdhci-esdhc-imx driver per review (see "Link:" above); always provide a valid host driver type. drivers/mmc/host/sdhci-esdhc-imx.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 6ab59d3e346f..931e383748a9 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -1142,6 +1142,20 @@ static void esdhc_reset_tuning(struct sdhci_host *host) } } +static void sdhci_esdhc_imx_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) +{ + /* + * This controller has no driver-type control: esdhc_writew_le() + * discards the driver-type field when writing SDHCI_HOST_CONTROL2. + * The programmed value is therefore irrelevant, but SDHCI rejects + * non-SD values such as 4 (eMMC 40 ohm, from fixed-emmc-driver-type). + * Force an always-valid Type B. + */ + ios->drv_type = MMC_SET_DRIVER_TYPE_B; + + sdhci_set_ios(mmc, ios); +} + static void usdhc_init_card(struct mmc_host *mmc, struct mmc_card *card) { struct sdhci_host *host = mmc_priv(mmc); @@ -1952,6 +1966,9 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev) host->max_timeout_count = 0xF; } + /* No SDHCI driver type control */ + host->mmc_host_ops.set_ios = sdhci_esdhc_imx_set_ios; + if (imx_data->socdata->flags & ESDHC_FLAG_MAN_TUNING) sdhci_esdhc_ops.platform_execute_tuning = esdhc_executing_tuning; -- 2.47.3