[...] > Sure > If the first card is sd2.0 since startup, dw_mci_switch_voltage will not be called, That can't be right. mmc_power_up() should trigger dw_mci_switch_voltage() to be invoked. > and card can be identified. But if UHS card is pulgged in first, the vqmmc will be down to 1.8v. > > when sd2.0 card is pulgged in, mmc core will call dw_mci_switch_voltage to change vqmmc to 3.3v > (MMC_SINGLE_VOTAGE_330). So vqmmc will be set 2.7v, if we request 2.7-3.6v. > > But vmmc is always 3.3v,becuase it be set min_volt = max_volt = 3.3v in dt tables. > > So the result: > vmmc = 3.3v and vqmmc = 2.7v, and sd2.0 card is failed to identify in my test. Hmm. I wonder why it works the first time? Could it be that your regulator have voltage ramp up time that isn't properly considered? Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
