[...] > > Could you please tell me the requirement of "op_code" parameter in > mmc_send_tuning()? > According to mmc_send_tuning(),it seems that tuning command(CMD19/CMD21) > is required. Thus device will not response mmc_send_tuning() if current > speed mode doesn't support tuning command. > Please correct me if I am wrong. > When the mmc core decides it's time to execute tuning, it invokes the ->execute_tuning() host ops, which has the "opcode" as a parameter. You should be able to use it when calling mmc_send_tuning(). [...] Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html