On 04/02/2016 03:42 AM, Heiko Stuebner wrote: > Am Mittwoch, 30. März 2016, 20:40:31 schrieb Jaehoon Chung: >> modified Rob's mail address. >> >> On 03/30/2016 04:24 PM, Guodong Xu wrote: >>> mmc registers may in abnormal state if mmc is used in bootloader, >>> eg. to support booting from eMMC. So we need reset mmc registers >>> when kernel boots up, instead of assuming mmc is in clean state. >> >> Do you mean mmc(card side) register or dwmmc host controller's register on >> host side? >> >> According to dwmmc controller TMR, there are two reset signals. One is >> reset_n, other is rst_n. It seems this patch is relevant to reset_n(For >> host). (rst_n is hardware reset for card.) >> >> So could you clarify better? Then it's helpful to me for understanding.. > > I think that actually means a reset of controller IP block logic, outside > the control of the dw_mmc block itself. > > On Rockchip SoCs this gets triggered from the CRU (clock and reset unit), so > I guess if I'm reading the manual correctly, should be the reset_n signal of > the ip block. > > rst_n on the other hand gets triggered through a dw_mmc register setting and > is already handled by the dw_mmc driver. Right, this patch is for reset_n signal. I didn't have seen the SoC that reset_n is designed. (Or i didn't realize...) If Rockchip is used from CRU (clock and reset unit), then i think that it makes sense. Thanks for explanation. Best Regards, Jaehoon Chung > > > Heiko > -- > 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 > > -- 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
