On 05-12 14:24, Jan Čermák wrote: > Date: Tue, 12 May 2026 14:24:35 +0200 > From: Jan Čermák <[email protected]> > To: [email protected] > Cc: Thomas Fitzsimmons <[email protected]>, Peng Fan <[email protected]>, > Jaehoon Chung <[email protected]>, Tom Rini <[email protected]>, > Matthias Brugger <[email protected]>, "Ivan T . Ivanov" > <[email protected]>, Jan Čermák <[email protected]> > Subject: [PATCH] mmc: bcmstb: Fix non-removable check in bcm2712 init > Message-ID: <[email protected]> > > 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 <[email protected]>
Reviewed-by: Ivan T. Ivanov <[email protected]> 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;
