[PATCH] mmc: bcmstb: Fix non-removable check in bcm2712 init

[Ivan T . Ivanov]

On 05-12 14:24, Jan Čermák wrote:
> Date: Tue, 12 May 2026 14:24:35 +0200
> From: Jan Čermák <sairon at sairon.cz>
> To: u-boot at lists.denx.de
> Cc: Thomas Fitzsimmons <fitzsim at fitzsim.org>, Peng Fan <peng.fan at nxp.com>,
>   Jaehoon Chung <jh80.chung at samsung.com>, Tom Rini <trini at konsulko.com>,
>   Matthias Brugger <mbrugger at suse.com>, "Ivan T . Ivanov"
>  <iivanov at suse.de>,  Jan Čermák <sairon at sairon.cz>
> Subject: [PATCH] mmc: bcmstb: Fix non-removable check in bcm2712 init
> Message-ID: <20260512122435.1118557-1-sairon at sairon.cz>
> 
> sdhci_brcmstb_init_2712() reads host->mmc->host_caps to decide whether
> to force card-detect for a non-removable eMMC, or to route the CD signal
> for a removable SD card. At the time this function runs from
> sdhci_bcmstb_probe(), however, host->mmc->host_caps is still zero, that
> field is only populated later by the MMC uclass, after the driver's
> probe returns. mmc_of_parse() has already filled plat->cfg.host_caps
> from the device tree by this point, so check that field instead.
> 
> Without the fix, every BCM2712 SDHCI instance takes the else branch and
> writes SDIO_CFG_SD_PIN_SEL = SDIO_CFG_SD_PIN_SEL_CARD (0x02), including
> the non-removable eMMC on boards such as CM5 on Home Assistant Yellow.
> The SDIO_CFG block lies outside the SDHCI core's reset scope, so this
> value persists across SDHCI_RESET_ALL into the next stage. On the
> BCM2712, having SD_PIN_SEL set to "SD" when the Linux kernel performs
> its first set_power(MMC_POWER_UP) write racily prevents the SDHCI
> POWER_ON bit from latching (see [1] for the whole backstory) - the
> voltage bits stick but POWER_ON drops - which wedges the first CMD0 the
> full 10 s software timeout. On Home Assistant Yellow this manifested as
> a ~20 s eMMC probe delay on roughly one in two Linux boots when U-Boot
> was the previous stage. Booting directly from the Pi firmware (no U-Boot
> in between) left SD_PIN_SEL at its default and did not exhibit the race.
> 
> Reading plat->cfg.host_caps lets init_2712 see the "non-removable"
> property and take the correct branch, leaving SD_PIN_SEL untouched for
> the eMMC.
> 
> [1] https://github.com/home-assistant/operating-system/pull/3700#issuecomment-4430229511
> 
> Fixes: 10127cdbab64 ("mmc: bcmstb: Add support for bcm2712 SD controller")
> Signed-off-by: Jan Čermák <sairon at sairon.cz>


Reviewed-by: Ivan T. Ivanov <iivanov at suse.de>

Thank you!

> ---
>  drivers/mmc/bcmstb_sdhci.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/bcmstb_sdhci.c b/drivers/mmc/bcmstb_sdhci.c
> index 7bddbebb162..f27b84a6ee4 100644
> --- a/drivers/mmc/bcmstb_sdhci.c
> +++ b/drivers/mmc/bcmstb_sdhci.c
> @@ -56,7 +56,7 @@ struct sdhci_brcmstb_dev_priv {
>  
>  static int sdhci_brcmstb_init_2712(struct udevice *dev)
>  {
> -	struct sdhci_host *host = dev_get_priv(dev);
> +	struct sdhci_bcmstb_plat *plat = dev_get_plat(dev);
>  	void *cfg_regs;
>  	u32 reg;
>  
> @@ -65,8 +65,8 @@ static int sdhci_brcmstb_init_2712(struct udevice *dev)
>  	if (!cfg_regs)
>  		return -ENOENT;
>  
> -	if ((host->mmc->host_caps & MMC_CAP_NONREMOVABLE) ||
> -	    (host->mmc->host_caps & MMC_CAP_NEEDS_POLL)) {
> +	if ((plat->cfg.host_caps & MMC_CAP_NONREMOVABLE) ||
> +	    (plat->cfg.host_caps & MMC_CAP_NEEDS_POLL)) {
>  		/* Force presence */
>  		reg = readl(cfg_regs + SDIO_CFG_CTRL);
>  		reg &= ~SDIO_CFG_CTRL_SDCD_N_TEST_LEV;