On 27 September 2012 12:39, Kevin Liu <keyuan.liu@xxxxxxxxx> wrote: > Hi, Ulf > > 2012/9/27 Ulf Hansson <ulf.hansson@xxxxxxxxxx>: >> Hi Kevin, >> >> On 26 September 2012 13:38, Kevin Liu <keyuan.liu@xxxxxxxxx> wrote: >>> From: Kevin Liu <kliu5@xxxxxxxxxxx> >>> >>> Mmc does NOT have special sequence requirements for 1.8v >>> signal voltage setting compared to sd and sdio. >>> Add a new 1.8v flag for mmc so as to use the same >>> start_signal_voltage_switch interface. >> >> This problem is protocol issue and should not be solved in the host >> driver. We have more issues for signal_voltage switch as well. >> >> Please have a look at Johan Rudholms patches: >> [PATCH v2 1/2] mmc: core: Proper signal voltage switch >> [PATCH v2 2/2] mmc: core: Power cycle card on voltage switch fail >> > I agree that we should do more things in protocal driver. > But the real voltage switch work is still done in host driver. If we > keep only one voltage switch interface, then we need to add a flag to > distinguish sd/sdio or emmc. Or we should define two interfaces to > call different host functions to handle this. > Johan's patches can't solve my issue. I understand that your driver today take care of specific things for sd/sdio. The reason for that is because of the protocol layer is not doing the voltage switch properly. The idea with Johans patches is resolve all these issues. Thus the host driver will just be responsible for the actual voltage switch to happen. So in the end your voltage switch function in the host is supposed to be rather simple. If you still think you need to handle sd/sdio/eMMC in a specific manner in your driver, there are always mmc_card_sdio|sd|mmc functions you can use. > > Thanks > Kevin Kind regards Ulf Hansson -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
